chore(preprod): add new compare features (#15841)

description + images of new comparison features

Author: mtopo27

docs/product/size-analysis/images/insight-diff.png

@@ -34,9 +34,24 @@ Size Analysis also provides actionable insights on how you can reduce your app's
 
 ### Build Comparison
 
-Compare any two builds to see what changed, review module-level diffs, and confirm that optimizations worked.
+Compare any two builds to see what changed, review module-level diffs, and confirm that optimizations worked. Build comparisons are automatically generated when [uploading as part of CI](/product/size-analysis/integrating-into-ci/), but can also be manually triggered for any two builds.
 
-![Build comparison screenshot placeholder](./images/build-comparison.png)
+#### Insight Diff
+
+The Insight diff shows the changes in insights between the two builds. This diff will show if a new insight is present in the build or if an insight as been addressed.
+
+![Build comparison - Insight Diff](./images/insight-diff.png)
+
+#### Table Diff
+
+The table diff shows every file change between the two builds. This diff will show if the file was added, removed, or changed. By default, the table hides changes under 500 B, but you can toggle this directly in the table.
+![Build comparison - Table Diff](./images/build-comparison.png)
+
+#### X-Ray Diff
+
+The X-Ray diff shows a visual representation of the file changes between the two builds. This diff will show if the file was added, removed, or changed.
+
+![Build comparison - X-ray Diff](./images/xray-diff.png)
 
 ### Status Checks