I assume Twitter .png files should be lossless and no artifacting and this here has more metadata as well.
I don't think so. Because I'd seen a lot of example in this site about post relationships. (example: post #2937188 and post #2936440, post #2936021 and post #2931948) I don't know too, about why Pixiv and Niconico Seiga .png files should be parent of Twitter .png files even they have less metadata than Twitter .png files, but many users did like that, so I will change parenting of this post.
