Requested feature overview description.
Detect the full resolution of the image on the upload page.
You could put it to the left of where the #whitelist-warning goes.
Example:
"W: 1280 × H: 720"
Why would it be useful?
Prevent user errors. Viewing the Image Info doesn't tell you the actual resolution of the image you are uploading, at least on Firefox.
What part(s) of the site page(s) are affected?
Upload page: https://e621.net/post/upload
Updated by fewrahuxo