On large reviews, it can be hard for a reviewer to track which files they've completed reviewing, if there are defects or discussions still ongoing. In that case, you don't want to mark the file as ...
The overall "accepted" check mark sort of does this for you.
The problem is when new versions are uploaded, it seem all check marks disappear.
If only the check marks dissappeared from a file that has a new version uploaded, then the check mark would allow you to see what still needs review.