It can be done. To submit a pixel you have to take a photo proof of your calculations on paper, it’s already “moderated”
Yes obviously it “can” be done, I’m suggesting it won’t for long, because there’s a big difference between submitting something to the site mods versus submitting something that is anonymously exposed to the public.
I’m saying this as the owner of a site where I made the mistake of allowing crowd-sourced image content to be anonymously served to others. It didn’t take long before not only was there NSFW content, but there was also illegal content.
* edit OH BTW I only just noticed this site was created by IQ, who has already dealt with this exact issue on ShaderToy and had to restrict and remove user submitted images due to abuse! The decision to not show people’s images is almost certainly intentional and by design.
If you compare them to nearby "correct" pixels, they usually just have one of the three RGB values that are sharply different.
But there’s no promise that they will. The photo feature may be more of an automated speed bump, a way to reduce silly answers and pixel spam, and let people self-select, than an active human moderation tool. Moderating is boring and expensive in time and/or money, why would anyone actually sift through thousands of hand-written pages of arithmetic?
2840 pages. Doesn't seem crazy. Page looks like it was written by hand? Next. At two pages per second it's less than half an hour of work.