Screenshot of the bug, where existing image is not shown on upload page.
There is no image shown when overwriting an existing image. See attached screenshot! =)
The screenshot is fairly self-explanatory, really.
I did recreate this bug, by uploading a second file, and it happened both time. The first time, I had EvilCat's theme. I've even disabled it to make sure it wasn't causing the bug.
Browser: Mozilla Firefox 220.127.116.11