Check source: this comes from a different Booru which has the same source as post #9350389 but this one is a PNG; I'm suspecting it's a lossy-lossless conversion of some sort by the site but not sure. It can't be uploaded by the commissioner as the file specifications are different per the Skeb request. The artifacting is lighter on this one when zoomed in and the Pixel Hashes are not the same.