Thread:VisualEditor/Feedback/Media/reply (2)

50379 is about the need to use unspecified default sizes, and it's still open.

Looking at the commit message, it appears that "set to original dimensions" means "set to the file's original dimensions". This is consistent with the behavior that you see.

This feature would be useful for small images, like File:Notepad icon small.svg, or if you needed to know the original dimensions so that you can figure out the correct proportion. However, in the current context (i.e., without these other useful and expected features present), that button looks more like a "generally undo whatever size changes I've made", so it's behavoir will be an unpleasant surprise for some editors.