diff --git a/src/sentry/preprod/vcs/pr_comments/snapshot_tasks.py b/src/sentry/preprod/vcs/pr_comments/snapshot_tasks.py
index 6fc82cb741671d..37b218c81ff420 100644
--- a/src/sentry/preprod/vcs/pr_comments/snapshot_tasks.py
+++ b/src/sentry/preprod/vcs/pr_comments/snapshot_tasks.py
@@ -13,7 +13,12 @@
 from sentry.preprod.models import PreprodArtifact, PreprodComparisonApproval
 from sentry.preprod.snapshots.models import PreprodSnapshotComparison, PreprodSnapshotMetrics
 from sentry.preprod.snapshots.utils import build_changes_map
-from sentry.preprod.vcs.pr_comments.snapshot_templates import format_snapshot_pr_comment
+from sentry.preprod.vcs.pr_comments.snapshot_templates import (
+    format_missing_base_snapshot_pr_comment,
+    format_snapshot_pr_comment,
+    format_solo_snapshot_pr_comment,
+    format_waiting_for_base_snapshot_pr_comment,
+)
 from sentry.preprod.vcs.pr_comments.tasks import find_existing_comment_id, save_pr_comment_result
 from sentry.shared_integrations.exceptions import ApiError
 from sentry.silo.base import SiloMode
@@ -38,7 +43,10 @@
     retry=Retry(times=3, delay=60),
 )
 def create_preprod_snapshot_pr_comment_task(
-    preprod_artifact_id: int, caller: str | None = None, **kwargs: Any
+    preprod_artifact_id: int,
+    caller: str | None = None,
+    is_timeout_check: bool = False,
+    **kwargs: Any,
 ) -> None:
     try:
         artifact = PreprodArtifact.objects.select_related(
@@ -155,46 +163,75 @@ def create_preprod_snapshot_pr_comment_task(
 
         base_artifact_map = PreprodArtifact.get_base_artifacts_for_commit(all_artifacts)
 
-        post_on_added = artifact.project.get_option(POST_ON_ADDED_OPTION_KEY, default=False)
-        post_on_removed = artifact.project.get_option(POST_ON_REMOVED_OPTION_KEY, default=True)
-        post_on_changed = artifact.project.get_option(POST_ON_CHANGED_OPTION_KEY, default=True)
-        post_on_renamed = artifact.project.get_option(POST_ON_RENAMED_OPTION_KEY, default=False)
-        changes_map = build_changes_map(
-            all_artifacts,
-            snapshot_metrics_map,
-            comparisons_map,
-            fail_on_added=post_on_added,
-            fail_on_removed=post_on_removed,
-            fail_on_changed=post_on_changed,
-            fail_on_renamed=post_on_renamed,
-        )
+        is_solo = not base_artifact_map
 
-        has_changes = any(changes_map.values())
-        # Failed comparisons are absent from changes_map (which only tracks
-        # SUCCESS state), so check comparisons_map directly to avoid
-        # suppressing failure reports.
-        has_failures = any(
-            c.state == PreprodSnapshotComparison.State.FAILED for c in comparisons_map.values()
-        )
-        if not has_changes and not has_failures:
-            logger.info(
-                "preprod.snapshot_pr_comments.create.skipped_no_diff",
-                extra={"artifact_id": artifact.id},
+        existing_comment_id = find_existing_comment_id(all_for_pr, "snapshots")
+        cc_id = cc.id
+
+        if is_solo:
+            app_ids = {a.app_id for a in all_artifacts if a.app_id}
+            has_previous_snapshots = (
+                PreprodSnapshotMetrics.objects.filter(
+                    preprod_artifact__project_id=artifact.project_id,
+                    preprod_artifact__app_id__in=app_ids,
+                )
+                .exclude(preprod_artifact__commit_comparison_id=commit_comparison.id)
+                .exists()
+                if app_ids
+                else False
             )
-            return
+            is_first_upload = not has_previous_snapshots
 
-        comment_body = format_snapshot_pr_comment(
-            all_artifacts,
-            snapshot_metrics_map,
-            comparisons_map,
-            base_artifact_map,
-            changes_map,
-            approvals_map=approvals_map,
-            project=artifact.project,
-        )
+            if is_first_upload or not commit_comparison.base_sha:
+                comment_body = format_solo_snapshot_pr_comment(
+                    all_artifacts, snapshot_metrics_map, project=artifact.project
+                )
+            elif not is_timeout_check:
+                comment_body = format_waiting_for_base_snapshot_pr_comment(
+                    all_artifacts, snapshot_metrics_map, project=artifact.project
+                )
+            else:
+                comment_body = format_missing_base_snapshot_pr_comment(
+                    all_artifacts, snapshot_metrics_map, project=artifact.project
+                )
+        else:
+            post_on_added = artifact.project.get_option(POST_ON_ADDED_OPTION_KEY, default=False)
+            post_on_removed = artifact.project.get_option(POST_ON_REMOVED_OPTION_KEY, default=True)
+            post_on_changed = artifact.project.get_option(POST_ON_CHANGED_OPTION_KEY, default=True)
+            post_on_renamed = artifact.project.get_option(POST_ON_RENAMED_OPTION_KEY, default=False)
+            changes_map = build_changes_map(
+                all_artifacts,
+                snapshot_metrics_map,
+                comparisons_map,
+                fail_on_added=post_on_added,
+                fail_on_removed=post_on_removed,
+                fail_on_changed=post_on_changed,
+                fail_on_renamed=post_on_renamed,
+            )
 
-        existing_comment_id = find_existing_comment_id(all_for_pr, "snapshots")
-        cc_id = cc.id
+            has_changes = any(changes_map.values())
+            # Failed comparisons are absent from changes_map (which only tracks
+            # SUCCESS state), so check comparisons_map directly to avoid
+            # suppressing failure reports.
+            has_failures = any(
+                c.state == PreprodSnapshotComparison.State.FAILED for c in comparisons_map.values()
+            )
+            if not has_changes and not has_failures and not existing_comment_id:
+                logger.info(
+                    "preprod.snapshot_pr_comments.create.skipped_no_diff",
+                    extra={"artifact_id": artifact.id},
+                )
+                return
+
+            comment_body = format_snapshot_pr_comment(
+                all_artifacts,
+                snapshot_metrics_map,
+                comparisons_map,
+                base_artifact_map,
+                changes_map,
+                approvals_map=approvals_map,
+                project=artifact.project,
+            )
 
     post_snapshot_pr_comment_task.delay(
         organization_id=organization.id,
diff --git a/src/sentry/preprod/vcs/pr_comments/snapshot_templates.py b/src/sentry/preprod/vcs/pr_comments/snapshot_templates.py
index a76f8aa833ea6a..f549522862b479 100644
--- a/src/sentry/preprod/vcs/pr_comments/snapshot_templates.py
+++ b/src/sentry/preprod/vcs/pr_comments/snapshot_templates.py
@@ -25,7 +25,6 @@ def format_snapshot_pr_comment(
     *,
     project: Project,
 ) -> str:
-    """Format a PR comment for snapshot comparisons."""
     if not artifacts:
         raise ValueError("Cannot format PR comment for empty artifact list")
 
@@ -90,12 +89,8 @@ def format_snapshot_pr_comment(
                 f" | {status} |"
             )
 
-    settings_url = project.organization.absolute_url(
-        f"/settings/projects/{project.slug}/mobile-builds/", query="tab=snapshots"
-    )
-
     table = f"{_HEADER}\n\n{COMPARISON_TABLE_HEADER}" + "\n".join(table_rows)
-    settings_link = f"[⚙️ {project.name} Snapshot Settings]({settings_url})"
+    settings_link = _format_settings_link(project)
 
     return f"{table}\n\n{settings_link}"
 
@@ -137,3 +132,76 @@ def _section_cell(count: int, section: str, artifact_url: str) -> str:
     if count > 0:
         return f"[{count}]({artifact_url}?selectedTypes={section})"
     return str(count)
+
+
+def _format_settings_link(project: Project) -> str:
+    settings_url = project.organization.absolute_url(
+        f"/settings/projects/{project.slug}/mobile-builds/", query="tab=snapshots"
+    )
+    return f"[⚙️ {project.name} Snapshot Settings]({settings_url})"
+
+
+def _format_solo_table(
+    artifacts: list[PreprodArtifact],
+    snapshot_metrics_map: dict[int, PreprodSnapshotMetrics],
+) -> str:
+    table_rows = []
+    for artifact in artifacts:
+        app_display, app_id = _app_display_info(artifact)
+        artifact_url = get_preprod_artifact_url(artifact, view_type="snapshots")
+        name_cell = _format_name_cell(app_display, app_id, artifact_url)
+        metrics = snapshot_metrics_map.get(artifact.id)
+        if metrics:
+            table_rows.append(
+                f"| {name_cell} | - | - | - | - | - | - | ✅ {metrics.image_count} uploaded |"
+            )
+        else:
+            table_rows.append(f"| {name_cell} | - | - | - | - | - | - | {PROCESSING_STATUS} |")
+    return f"{_HEADER}\n\n{COMPARISON_TABLE_HEADER}" + "\n".join(table_rows)
+
+
+_SOLO_MESSAGE = "Snapshot diffs will appear when we have a base upload to compare against. Make sure to upload snapshots from your main branch."
+_WAITING_MESSAGE = "Waiting for base snapshots to finish uploading. This comment will update automatically within ~10 minutes or fail."
+_MISSING_BASE_MESSAGE = "No base snapshots found to compare against. Make sure snapshots are uploaded from your main branch."
+
+
+def _format_solo_comment(
+    artifacts: list[PreprodArtifact],
+    snapshot_metrics_map: dict[int, PreprodSnapshotMetrics],
+    message: str,
+    *,
+    project: Project,
+) -> str:
+    if not artifacts:
+        raise ValueError("Cannot format PR comment for empty artifact list")
+    table = _format_solo_table(artifacts, snapshot_metrics_map)
+    return f"{table}\n\n{message}\n\n{_format_settings_link(project)}"
+
+
+def format_solo_snapshot_pr_comment(
+    artifacts: list[PreprodArtifact],
+    snapshot_metrics_map: dict[int, PreprodSnapshotMetrics],
+    *,
+    project: Project,
+) -> str:
+    return _format_solo_comment(artifacts, snapshot_metrics_map, _SOLO_MESSAGE, project=project)
+
+
+def format_waiting_for_base_snapshot_pr_comment(
+    artifacts: list[PreprodArtifact],
+    snapshot_metrics_map: dict[int, PreprodSnapshotMetrics],
+    *,
+    project: Project,
+) -> str:
+    return _format_solo_comment(artifacts, snapshot_metrics_map, _WAITING_MESSAGE, project=project)
+
+
+def format_missing_base_snapshot_pr_comment(
+    artifacts: list[PreprodArtifact],
+    snapshot_metrics_map: dict[int, PreprodSnapshotMetrics],
+    *,
+    project: Project,
+) -> str:
+    return _format_solo_comment(
+        artifacts, snapshot_metrics_map, _MISSING_BASE_MESSAGE, project=project
+    )
diff --git a/src/sentry/preprod/vcs/status_checks/snapshots/tasks.py b/src/sentry/preprod/vcs/status_checks/snapshots/tasks.py
index be538749f0c5ce..315ee36a2d1e2b 100644
--- a/src/sentry/preprod/vcs/status_checks/snapshots/tasks.py
+++ b/src/sentry/preprod/vcs/status_checks/snapshots/tasks.py
@@ -16,6 +16,7 @@
 from sentry.preprod.snapshots.models import PreprodSnapshotComparison, PreprodSnapshotMetrics
 from sentry.preprod.snapshots.utils import build_changes_map
 from sentry.preprod.url_utils import get_preprod_artifact_url
+from sentry.preprod.vcs.pr_comments.snapshot_tasks import create_preprod_snapshot_pr_comment_task
 from sentry.preprod.vcs.status_checks.snapshots.templates import (
     format_first_snapshot_status_check_messages,
     format_generated_snapshot_status_check_messages,
@@ -319,6 +320,14 @@ def create_preprod_snapshot_status_check_task(
             },
             countdown=MISSING_BASE_GRACE_PERIOD_SECONDS,
         )
+        create_preprod_snapshot_pr_comment_task.apply_async(
+            kwargs={
+                "preprod_artifact_id": preprod_artifact_id,
+                "caller": "missing_base_timeout",
+                "is_timeout_check": True,
+            },
+            countdown=MISSING_BASE_GRACE_PERIOD_SECONDS,
+        )
 
 
 def _compute_snapshot_status(
diff --git a/tests/sentry/preprod/vcs/pr_comments/test_snapshot_tasks.py b/tests/sentry/preprod/vcs/pr_comments/test_snapshot_tasks.py
index eeec784d9afa50..d53527ea469833 100644
--- a/tests/sentry/preprod/vcs/pr_comments/test_snapshot_tasks.py
+++ b/tests/sentry/preprod/vcs/pr_comments/test_snapshot_tasks.py
@@ -84,13 +84,15 @@ def _create_artifact_with_metrics(
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.build_changes_map")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_snapshot_pr_comment")
+    @patch("sentry.preprod.models.PreprodArtifact.get_base_artifacts_for_commit")
     def test_dispatches_subtask(
-        self, mock_format, mock_get_client, mock_build_changes_map, mock_delay
+        self, mock_get_base, mock_format, mock_get_client, mock_build_changes_map, mock_delay
     ):
         mock_get_client.return_value = Mock()
         mock_format.return_value = "## Sentry Snapshot Testing\n..."
 
         artifact, metrics = self._create_artifact_with_metrics()
+        mock_get_base.return_value = {artifact.id: Mock()}
         mock_build_changes_map.return_value = {artifact.id: True}
 
         with self.feature(self._feature):
@@ -112,8 +114,9 @@ def test_dispatches_subtask(
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.build_changes_map")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_snapshot_pr_comment")
+    @patch("sentry.preprod.models.PreprodArtifact.get_base_artifacts_for_commit")
     def test_dispatches_with_existing_comment_id(
-        self, mock_format, mock_get_client, mock_build_changes_map, mock_delay
+        self, mock_get_base, mock_format, mock_get_client, mock_build_changes_map, mock_delay
     ):
         mock_get_client.return_value = Mock()
         mock_format.return_value = "updated body"
@@ -134,6 +137,7 @@ def test_dispatches_with_existing_comment_id(
         artifact, metrics = self._create_artifact_with_metrics(
             commit_comparison=commit_comparison,
         )
+        mock_get_base.return_value = {artifact.id: Mock()}
         mock_build_changes_map.return_value = {artifact.id: True}
 
         with self.feature(self._feature):
@@ -265,8 +269,9 @@ def test_skips_nonexistent_artifact(self, mock_get_client):
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.build_changes_map")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_snapshot_pr_comment")
+    @patch("sentry.preprod.models.PreprodArtifact.get_base_artifacts_for_commit")
     def test_reads_fresh_extras_via_select_for_update(
-        self, mock_format, mock_get_client, mock_build_changes_map, mock_delay
+        self, mock_get_base, mock_format, mock_get_client, mock_build_changes_map, mock_delay
     ):
         mock_get_client.return_value = Mock()
         mock_format.return_value = "updated body"
@@ -286,6 +291,7 @@ def test_reads_fresh_extras_via_select_for_update(
         artifact, metrics = self._create_artifact_with_metrics(
             commit_comparison=commit_comparison,
         )
+        mock_get_base.return_value = {artifact.id: Mock()}
         mock_build_changes_map.return_value = {artifact.id: True}
 
         CommitComparison.objects.filter(id=commit_comparison.id).update(
@@ -302,8 +308,9 @@ def test_reads_fresh_extras_via_select_for_update(
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.build_changes_map")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_snapshot_pr_comment")
+    @patch("sentry.preprod.models.PreprodArtifact.get_base_artifacts_for_commit")
     def test_updates_comment_from_previous_commit(
-        self, mock_format, mock_get_client, mock_build_changes_map, mock_delay
+        self, mock_get_base, mock_format, mock_get_client, mock_build_changes_map, mock_delay
     ):
         mock_get_client.return_value = Mock()
         mock_format.return_value = "updated body"
@@ -336,6 +343,7 @@ def test_updates_comment_from_previous_commit(
         )
 
         artifact, metrics = self._create_artifact_with_metrics(commit_comparison=cc_b)
+        mock_get_base.return_value = {artifact.id: Mock()}
         mock_build_changes_map.return_value = {artifact.id: True}
 
         with self.feature(self._feature):
@@ -348,8 +356,9 @@ def test_updates_comment_from_previous_commit(
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.build_changes_map")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_snapshot_pr_comment")
+    @patch("sentry.preprod.models.PreprodArtifact.get_base_artifacts_for_commit")
     def test_passes_post_on_options_to_build_changes_map(
-        self, mock_format, mock_get_client, mock_build_changes_map, mock_delay
+        self, mock_get_base, mock_format, mock_get_client, mock_build_changes_map, mock_delay
     ):
         mock_get_client.return_value = Mock()
         mock_format.return_value = "body"
@@ -360,6 +369,7 @@ def test_passes_post_on_options_to_build_changes_map(
         self.project.update_option("sentry:preprod_snapshot_pr_comments_post_on_renamed", True)
 
         artifact, metrics = self._create_artifact_with_metrics()
+        mock_get_base.return_value = {artifact.id: Mock()}
         mock_build_changes_map.return_value = {artifact.id: True}
 
         with self.feature(self._feature):
@@ -376,8 +386,9 @@ def test_passes_post_on_options_to_build_changes_map(
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.build_changes_map")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
     @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_snapshot_pr_comment")
+    @patch("sentry.preprod.models.PreprodArtifact.get_base_artifacts_for_commit")
     def test_creates_when_no_sibling_has_comment_id(
-        self, mock_format, mock_get_client, mock_build_changes_map, mock_delay
+        self, mock_get_base, mock_format, mock_get_client, mock_build_changes_map, mock_delay
     ):
         mock_get_client.return_value = Mock()
         mock_format.return_value = "new body"
@@ -407,6 +418,7 @@ def test_creates_when_no_sibling_has_comment_id(
         )
 
         artifact, metrics = self._create_artifact_with_metrics(commit_comparison=cc_b)
+        mock_get_base.return_value = {artifact.id: Mock()}
         mock_build_changes_map.return_value = {artifact.id: True}
 
         with self.feature(self._feature):
@@ -416,6 +428,173 @@ def test_creates_when_no_sibling_has_comment_id(
         assert mock_delay.call_args.kwargs["existing_comment_id"] is None
 
 
+@cell_silo_test
+class CreateSnapshotPrCommentSoloTest(CreatePreprodSnapshotPrCommentTaskTest):
+    def _create_previous_snapshot(self, app_id: str = "com.example.app") -> None:
+        prev_cc = CommitComparison.objects.create(
+            organization_id=self.organization.id,
+            head_sha="prev" + "0" * 36,
+            base_sha="prev" + "1" * 36,
+            provider="github",
+            head_repo_name="owner/repo",
+            base_repo_name="owner/repo",
+            head_ref="main",
+            base_ref="main",
+            pr_number=None,
+        )
+        prev_artifact = self.create_preprod_artifact(
+            project=self.project,
+            state=PreprodArtifact.ArtifactState.PROCESSED,
+            app_id=app_id,
+            commit_comparison=prev_cc,
+        )
+        PreprodSnapshotMetrics.objects.create(preprod_artifact=prev_artifact, image_count=5)
+
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.post_snapshot_pr_comment_task.delay")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_solo_snapshot_pr_comment")
+    def test_no_base_sha_posts_solo_comment(self, mock_format_solo, mock_get_client, mock_delay):
+        mock_get_client.return_value = Mock()
+        mock_format_solo.return_value = "solo body"
+
+        unique = str(uuid.uuid4()).replace("-", "")[:8]
+        cc = CommitComparison.objects.create(
+            organization_id=self.organization.id,
+            head_sha=unique.ljust(40, "a"),
+            base_sha=None,
+            provider="github",
+            head_repo_name="owner/repo",
+            base_repo_name="owner/repo",
+            head_ref="feature/test",
+            base_ref="main",
+            pr_number=42,
+        )
+
+        artifact, _ = self._create_artifact_with_metrics(commit_comparison=cc)
+
+        with self.feature(self._feature):
+            create_preprod_snapshot_pr_comment_task(artifact.id)
+
+        mock_format_solo.assert_called_once()
+        mock_delay.assert_called_once()
+        assert mock_delay.call_args.kwargs["comment_body"] == "solo body"
+
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.post_snapshot_pr_comment_task.delay")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_solo_snapshot_pr_comment")
+    def test_first_upload_with_base_sha_posts_solo_comment(
+        self, mock_format_solo, mock_get_client, mock_delay
+    ):
+        mock_get_client.return_value = Mock()
+        mock_format_solo.return_value = "first upload body"
+
+        artifact, _ = self._create_artifact_with_metrics()
+
+        with self.feature(self._feature):
+            create_preprod_snapshot_pr_comment_task(artifact.id)
+
+        mock_format_solo.assert_called_once()
+        mock_delay.assert_called_once()
+        assert mock_delay.call_args.kwargs["comment_body"] == "first upload body"
+
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.post_snapshot_pr_comment_task.delay")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
+    @patch(
+        "sentry.preprod.vcs.pr_comments.snapshot_tasks.format_waiting_for_base_snapshot_pr_comment"
+    )
+    def test_base_sha_no_match_posts_waiting_comment(
+        self, mock_format_waiting, mock_get_client, mock_delay
+    ):
+        mock_get_client.return_value = Mock()
+        mock_format_waiting.return_value = "waiting body"
+
+        self._create_previous_snapshot()
+        artifact, _ = self._create_artifact_with_metrics()
+
+        with self.feature(self._feature):
+            create_preprod_snapshot_pr_comment_task(artifact.id)
+
+        mock_format_waiting.assert_called_once()
+        mock_delay.assert_called_once()
+        assert mock_delay.call_args.kwargs["comment_body"] == "waiting body"
+
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.post_snapshot_pr_comment_task.delay")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_missing_base_snapshot_pr_comment")
+    def test_timeout_posts_missing_base_comment(
+        self, mock_format_missing, mock_get_client, mock_delay
+    ):
+        mock_get_client.return_value = Mock()
+        mock_format_missing.return_value = "missing body"
+
+        self._create_previous_snapshot()
+        artifact, _ = self._create_artifact_with_metrics()
+
+        with self.feature(self._feature):
+            create_preprod_snapshot_pr_comment_task(artifact.id, is_timeout_check=True)
+
+        mock_format_missing.assert_called_once()
+        mock_delay.assert_called_once()
+        assert mock_delay.call_args.kwargs["comment_body"] == "missing body"
+
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.post_snapshot_pr_comment_task.delay")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.build_changes_map")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_snapshot_pr_comment")
+    @patch("sentry.preprod.models.PreprodArtifact.get_base_artifacts_for_commit")
+    def test_timeout_with_base_arrived_runs_normal_path(
+        self, mock_get_base, mock_format_normal, mock_get_client, mock_build_changes_map, mock_delay
+    ):
+        mock_get_client.return_value = Mock()
+        mock_format_normal.return_value = "normal body"
+
+        head_artifact, head_metrics = self._create_artifact_with_metrics()
+        mock_get_base.return_value = {head_artifact.id: Mock()}
+        mock_build_changes_map.return_value = {head_artifact.id: True}
+
+        with self.feature(self._feature):
+            create_preprod_snapshot_pr_comment_task(head_artifact.id, is_timeout_check=True)
+
+        mock_format_normal.assert_called_once()
+        mock_delay.assert_called_once()
+        assert mock_delay.call_args.kwargs["comment_body"] == "normal body"
+
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.post_snapshot_pr_comment_task.delay")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.build_changes_map")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.get_commit_context_client")
+    @patch("sentry.preprod.vcs.pr_comments.snapshot_tasks.format_snapshot_pr_comment")
+    @patch("sentry.preprod.models.PreprodArtifact.get_base_artifacts_for_commit")
+    def test_updates_existing_comment_when_no_changes(
+        self, mock_get_base, mock_format, mock_get_client, mock_build_changes_map, mock_delay
+    ):
+        mock_get_client.return_value = Mock()
+        mock_format.return_value = "unchanged body"
+
+        cc = CommitComparison.objects.create(
+            organization_id=self.organization.id,
+            head_sha="a" * 40,
+            base_sha="b" * 40,
+            provider="github",
+            head_repo_name="owner/repo",
+            base_repo_name="owner/repo",
+            head_ref="feature/test",
+            base_ref="main",
+            pr_number=42,
+            extras={"pr_comments": {"snapshots": {"success": True, "comment_id": "waiting_123"}}},
+        )
+
+        head_artifact, _ = self._create_artifact_with_metrics(commit_comparison=cc)
+        mock_get_base.return_value = {head_artifact.id: Mock()}
+        mock_build_changes_map.return_value = {head_artifact.id: False}
+
+        with self.feature(self._feature):
+            create_preprod_snapshot_pr_comment_task(head_artifact.id)
+
+        mock_format.assert_called_once()
+        mock_delay.assert_called_once()
+        assert mock_delay.call_args.kwargs["existing_comment_id"] == "waiting_123"
+
+
 @cell_silo_test
 class PostSnapshotPrCommentTaskTest(TestCase):
     def setUp(self) -> None:
diff --git a/tests/sentry/preprod/vcs/pr_comments/test_snapshot_templates.py b/tests/sentry/preprod/vcs/pr_comments/test_snapshot_templates.py
index 495950b64ae7ac..48d9d0633dd2dc 100644
--- a/tests/sentry/preprod/vcs/pr_comments/test_snapshot_templates.py
+++ b/tests/sentry/preprod/vcs/pr_comments/test_snapshot_templates.py
@@ -5,7 +5,10 @@
 from sentry.preprod.models import PreprodArtifact, PreprodComparisonApproval
 from sentry.preprod.snapshots.models import PreprodSnapshotComparison, PreprodSnapshotMetrics
 from sentry.preprod.vcs.pr_comments.snapshot_templates import (
+    format_missing_base_snapshot_pr_comment,
     format_snapshot_pr_comment,
+    format_solo_snapshot_pr_comment,
+    format_waiting_for_base_snapshot_pr_comment,
 )
 from sentry.testutils.cases import TestCase
 from sentry.testutils.silo import cell_silo_test
@@ -424,3 +427,79 @@ def test_no_base_app_id_shown(self) -> None:
         )
 
         assert "`com.example.myapp`" in result
+
+
+@cell_silo_test
+class FormatSoloPrCommentTest(SnapshotPrCommentTestBase):
+    def test_solo_shows_uploaded_count_and_first_upload_message(self) -> None:
+        artifact, metrics = self._create_artifact_with_metrics(app_name="My App", image_count=7)
+
+        result = format_solo_snapshot_pr_comment(
+            [artifact], {artifact.id: metrics}, project=self.project
+        )
+
+        assert "## Sentry Snapshot Testing" in result
+        assert "7 uploaded" in result
+        assert "My App" in result
+        assert "Snapshot diffs will appear when we have a base upload to compare against" in result
+        assert "main branch" in result
+        assert f"/settings/projects/{self.project.slug}/mobile-builds/" in result
+        assert "tab=snapshots" in result
+        assert f"{self.project.name} Snapshot Settings" in result
+
+    def test_solo_empty_artifacts_raises(self) -> None:
+        with pytest.raises(ValueError, match="Cannot format PR comment for empty artifact list"):
+            format_solo_snapshot_pr_comment([], {}, project=self.project)
+
+    def test_solo_multiple_artifacts(self) -> None:
+        artifact1, metrics1 = self._create_artifact_with_metrics(
+            app_id="com.example.app1", build_number=1, image_count=3
+        )
+        artifact2, metrics2 = self._create_artifact_with_metrics(
+            app_id="com.example.app2", build_number=2, image_count=5
+        )
+
+        result = format_solo_snapshot_pr_comment(
+            [artifact1, artifact2],
+            {artifact1.id: metrics1, artifact2.id: metrics2},
+            project=self.project,
+        )
+
+        assert "com.example.app1" in result
+        assert "com.example.app2" in result
+        assert "3 uploaded" in result
+        assert "5 uploaded" in result
+
+    def test_waiting_for_base_shows_waiting_message(self) -> None:
+        artifact, metrics = self._create_artifact_with_metrics(image_count=4)
+
+        result = format_waiting_for_base_snapshot_pr_comment(
+            [artifact], {artifact.id: metrics}, project=self.project
+        )
+
+        assert "## Sentry Snapshot Testing" in result
+        assert "4 uploaded" in result
+        assert "Waiting for base snapshots to finish uploading" in result
+        assert "~10 minutes" in result
+        assert f"/settings/projects/{self.project.slug}/mobile-builds/" in result
+
+    def test_waiting_for_base_empty_artifacts_raises(self) -> None:
+        with pytest.raises(ValueError, match="Cannot format PR comment for empty artifact list"):
+            format_waiting_for_base_snapshot_pr_comment([], {}, project=self.project)
+
+    def test_missing_base_shows_failure_message(self) -> None:
+        artifact, metrics = self._create_artifact_with_metrics(image_count=2)
+
+        result = format_missing_base_snapshot_pr_comment(
+            [artifact], {artifact.id: metrics}, project=self.project
+        )
+
+        assert "## Sentry Snapshot Testing" in result
+        assert "2 uploaded" in result
+        assert "No base snapshots found to compare against" in result
+        assert "main branch" in result
+        assert f"/settings/projects/{self.project.slug}/mobile-builds/" in result
+
+    def test_missing_base_empty_artifacts_raises(self) -> None:
+        with pytest.raises(ValueError, match="Cannot format PR comment for empty artifact list"):
+            format_missing_base_snapshot_pr_comment([], {}, project=self.project)
diff --git a/tests/sentry/preprod/vcs/status_checks/snapshots/test_tasks.py b/tests/sentry/preprod/vcs/status_checks/snapshots/test_tasks.py
index fc89330fe061c0..48f173de791466 100644
--- a/tests/sentry/preprod/vcs/status_checks/snapshots/test_tasks.py
+++ b/tests/sentry/preprod/vcs/status_checks/snapshots/test_tasks.py
@@ -423,9 +423,15 @@ def _create_solo_head_artifact(self):
     @patch(f"{TASK_MODULE}.post_snapshot_status_check_task")
     @patch(f"{TASK_MODULE}.get_status_check_provider")
     @patch(f"{TASK_MODULE}.get_status_check_client")
+    @patch(f"{TASK_MODULE}.create_preprod_snapshot_pr_comment_task")
     @patch(f"{TASK_MODULE}.create_preprod_snapshot_status_check_task.apply_async")
     def test_missing_base_first_attempt_posts_in_progress(
-        self, mock_apply_async, mock_get_client, mock_get_provider, mock_post_task
+        self,
+        mock_status_apply_async,
+        mock_pr_comment_task,
+        mock_get_client,
+        mock_get_provider,
+        mock_post_task,
     ):
         mock_get_client.return_value = (Mock(), Mock())
         mock_get_provider.return_value = Mock()
@@ -441,11 +447,18 @@ def test_missing_base_first_attempt_posts_in_progress(
         call_kwargs = mock_post_task.delay.call_args[1]
         assert call_kwargs["status"] == StatusCheckStatus.IN_PROGRESS.value
 
-        mock_apply_async.assert_called_once()
-        async_kwargs = mock_apply_async.call_args[1]
-        assert async_kwargs["kwargs"]["is_timeout_check"] is True
-        assert async_kwargs["kwargs"]["preprod_artifact_id"] == artifact.id
-        assert async_kwargs["countdown"] == 600
+        mock_status_apply_async.assert_called_once()
+        status_kwargs = mock_status_apply_async.call_args[1]
+        assert status_kwargs["kwargs"]["is_timeout_check"] is True
+        assert status_kwargs["kwargs"]["preprod_artifact_id"] == artifact.id
+        assert status_kwargs["countdown"] == 600
+
+        mock_pr_comment_task.apply_async.assert_called_once()
+        pr_kwargs = mock_pr_comment_task.apply_async.call_args[1]
+        assert pr_kwargs["kwargs"]["is_timeout_check"] is True
+        assert pr_kwargs["kwargs"]["preprod_artifact_id"] == artifact.id
+        assert pr_kwargs["kwargs"]["caller"] == "missing_base_timeout"
+        assert pr_kwargs["countdown"] == 600
 
     @patch(f"{TASK_MODULE}.post_snapshot_status_check_task")
     @patch(f"{TASK_MODULE}.get_status_check_provider")