Observe: From here, there is no way to go backward or exit the forum. It is necessary to force quit the app
Expected: Tapping or scrolling the image should present a way to escape from the image view.
Same thing on Android, but you can always click the back button
Interesting. Does swiping left-to-right bring you back?
Update: I had a chance to test, and swiping horizontally from left to right performs the back gesture and returns the user back to Discourse. You can also swipe from up to down, that’s a gesture to dismiss the webview, it will bring you back to the site list of the app.
For the record, this issue doesn’t affect meta, because meta has CDN for assets and the Download link is treated like an external link by the app, that is it sends that link to Safari.
After further experimentation, the issue of the controls no longer coming back only happens with images which are larger than the screen.
It turns out that I can navigate backward if I swipe right from the very edge of the screen. I didn’t know about that gesture as my phone case has raised edges around the screen, and that gesture doesn’t have much tolerance on how close to the screen edge the gesture must begin. That makes it difficult to discover.