While I understand that art on AO3 for anon challenges/fests has been done before, I'm just not comfortable settling, compromising, and accommodating for a site that isn't yet ready to host visuals as stand alone works. This has nothing to do with you, but my personal boycott against AO3 and using them as a home for my work because they have yet to support visuals in a way that showcases artists. Until AO3 is at a place where all fandom works gets presented right, I'd rather not use their site.

I actually quite like xsmoonshine's suggestion about using LJ for art (like in past years), but I completely understand if you don't want to bend over backwards for one person.