The sizes in pixels and bytes are identical. They are embed in 2 FLAC files (44.1/16), but then i tried it with 2 mp3 files as well. The result is the same. Selected both file: image viewer in both Tag Panel and Extended Tag Panel shows the first image (depending on the order in the list), instead of NOT showing image, with text "Cover varies".
There are additional diagnostic options, but i am more interested in the experience of others. Or if Florian ask for something.
Hmm... The forum motor resizes the images. Here are the originals: front 1.jpg front 2.jpg
I think I've used this as a performance tweak, where I use the amount of covers in the files as first criteria and the size in bytes as second criteria (only if all selected files have the same amount of covers). I knew it wasn't 100% correct, but secretly hoped this day with this bug report would never come.
Comparing content would make this comparison always necessary, e.g., for albums where each track has the same cover. I'll look into it again.