Requested feature overview description.
When you are on https://e621.net/posts page and keep your cursor over an image long enough a tooltip will appear.
Tooltip should have information about the image like : 1920x1080.png, 1337 kB

Why would it be useful?
It would be faster to look at image information for multiple images and roughly determine if there is some inferior image among them.

What part(s) of the site page(s) are affected?
https://e621.net/posts page tooltips