Story thumbnails are shown by the extension if a photo modal is taking a long time to load

[ehmorris]

Expected Behavior

If a photo loading placeholder is clicked, the extension should either not display at all, or display in a loading state.

Actual Behavior

If a photo loading placeholder is clicked, in the photo modal, an asset from "behind" the modal may be detected e.g. a story thumbnail, and attached to the UI even after the photo has loaded.

Steps To Reproduce The Behavior

• Go to a profile
• Open a photo in the photo modal
• Throttle your connection so the photo takes a while to load
• Click on the blank area where the photo will appear to show the extension
• If a story thumbnail is at the coordinates where you clicked, the extension will attach to its url and show a very small thumbnail instead of the modal photo.