Curious about this. Maybe I just never noticed, or maybe this was something recently added, not sure.
When you open an image post to comment and hover over the small image, a white banner appears with a couple of icons to select. It seems there is no difference between clicking on the image, or the icons in the banner, all three simply open the larger view. So I’m not sure what that white banner is needed when hovering over the image.
No biggie really, just curious. If there’s a new feature coming, that’s probably why, otherwise, just clicking on the image seems simple enough.