The commentary says that this is a "re-draft", which makes it sound like it's a revision of this, but I can't see any differences between the two. And bizarrely, the uploader says that this is a "duplicate" with the exact dimensions and file size, yet didn't automatically redirect to this post like it normally does when you attempt to uplaod such an apparently identical duplicate. What's going on?

MarqFJA87 said in comment #2634187:

The commentary says that this is a "re-draft", which makes it sound like it's a revision of this, but I can't see any differences between the two. And bizarrely, the uploader says that this is a "duplicate" with the exact dimensions and file size, yet didn't automatically redirect to this post like it normally does when you attempt to uplaod such an apparently identical duplicate. What's going on?

再稿 means re-upload/re-post/re-submission (再投稿) in the context of sns, so no changes is to be expected.
Dunno why the uploader wouldn't pick it up as a dupe though.