All those illustrations are CC-By David Revoy : https://www.davidrevoy.com/article800/mobilizon
https://framablog.org/wp-content/uploads/2020/10/2020-10-06-...
https://framablog.org/wp-content/uploads/2020/10/2020-10-08-...
(Not sure if these are linked anywhere, but I just chopped the image size out of the URL.)
Online demo: http://waifu2x.udp.jp/
Repo: https://github.com/nagadomi/waifu2x
Reddit discussion: https://www.reddit.com/r/VRchat/comments/bkw543/tutorial_how...