I don't know what you're screenshot is supposed to tell me. Can you be more specific about reproduction instructions (OS, Browser, expected results). This behaves as expected on iOS Chrome and Safari.

https://secure.phabricator.com/book/phabcontrib/article/bug_reports/ has a bit more detail, we're trying to get the full steps to reproducing bugs when filed now so we can reduce back and forth time.

Android 4.4.2 (also happens on 4.1 but I know it's too old, and I will replace this 4.1 next month...)
Google Chrome for Android 46.0.2490.76

when I try to download random images...

Expected: download successful, I can open it
Actual: download never completes.

Looks like Android browsers hand off downloads to a different application, that it isn't the browser downloading the file.

Yeah, I'm on Android 6 and it seems to happen consistently. Yes, as far as I know Chrome on Android hands off downloads to the "Downloads" application. Steps to reproduce are basically:

1. Click on an image thumbnail to open up the full-screen view.
2. Click "Download".
3. Download doesn't complete.

Maybe due to T5685 ?