I believe Steam removed them because of payment processors complaining because of external influence, so it is a legal problem, they are mostly removing incest. I am not familiar with what was removed but it looks like NSFW slop... Still sets a bad precedent for the livelihood of good NSFW games.

Yeah, it can be tricky sometimes. You can find it to the right of the HTTPS lock on the address bar, or you can press on that lock icon, press "connection secure", then "more information", and on the window that pops up, go to permissions and look for "extract canvas data", that should be it.

Do you use Librewolf? You have to allow HTML5 Canvas access to the site, I have seen these artifacts in Librewolf when uploading images or sometimes when seeing images. Hope it helps!