In file-pages for images that contain transparency, eg [[File:Blue DualShock.png]] if the mouse-pointer is over the image, the transparency shows as the checkerboard pattern. However, if the mouse-pointer is moved away from the image, the background changes to white.
It might be worth examining whether this aspect should be incorporated into Media Viewer.
Version: unspecified
Severity: enhancement
See bug 57620 for the motivation. At the time we run into problems with black-on-transparent images; white-on-transparent is less frequent but does exist, e.g. [[File:Disqus_d_icon_official_-_white_on_transparent_background.png]]
Ah, I see how the edge-cases would cause problems and confusion. :/
Ok, well, feel free to close this bug however appropriate. At least it will serve as a search result, if anyone else tries to enter a duplicate. :)