Trace a missing or replaced image

Follow artwork from the catalog field to the image request and the pixels on the test device.

The catalog changed. Why is the old poster still on screen?

Treat the catalog response, artwork request and rendered image as three separate observations. Use an image you own and a synthetic test item with an unmistakable poster.

  1. Inspect the reference. Refresh the item and select the catalog request in Explorer. Check the actual artwork field returned to the client.
  2. Find the fetch. Locate the next image request. Compare its final host, path and query with the rule: an app may resolve a relative URL or ask for a resized variant. If there is no new request, record that observation; it does not by itself prove a cache hit.
  3. Review the replacement. Check the scoped matcher, content type and dimensions before activating a local override. When changing both JSON and image bytes, keep them together in an Effect Bundle.
  4. Verify delivery, then rendering. Refresh again and select the matching image request. Check whether the intended replacement was actually served. A local asset marked unreadable isn’t an upstream HTTP error. Even a completed transfer doesn’t prove the poster appeared: look at the app separately.

Disable the test effect and repeat with ordinary routing. Keep the catalog and image observations together when handing off a bug; note explicitly if either request was absent.