Curious; he's also posted this image to Pixiv, but Danbooru rejects my attempted upload of that version because it considers the two to be identical. Apparently, there's not even a difference in file size from compression, it seems. The only difference, I guess, is in the artist commentary:

ストレスを感じると顔をしかめるフレンズ

A Friend who grimaces when she feels stress.

Moonspeaker said:

Curious; he's also posted this image to Pixiv, but Danbooru rejects my attempted upload of that version because it considers the two to be identical. Apparently, there's not even a difference in file size from compression, it seems. The only difference, I guess, is in the artist commentary:

If MD5 hash check is match with old upload, Danbooru will reject new upload even from different source.

Why does this have Kantai Collection tags?

Wogerno said:

Why does this have Kantai Collection tags?

Because technically "Muppo" is a caricature of Northern Ocean Hime so any picture involving Muppo invariably relate to the Kantai Collection tag.