source:https://cdn.discordapp.com/attachments/
I don't think Discord is that acceptable as a source, but I see some have provided it as such anyway. It's better than nothing, yes, but it provides extremely marginal use, and it is known that Discord will intentionally sample uploaded images to save on bandwidth. Moreover I doubt that artists are actually using Discord as a channel to upload and share their work... seems kind of off.
For now I would consider all of these as image samples, but we can't really determine where the original is without doing some extensive digging. It just seems too laissez-faire to accept these things -- as I imagine some might come from friends just sharing what they find on a server without actually sharing any original links.
Anyways, for now since there's such a low count, I assume we can at least ask the original uploaders (if possible) to provide as original a link if possible/known, otherwise we're just going to have to wait on some of these.
Updated