I figured I would explain this a little bit just in case there's still confusion about it. We're going to possibly make changes next round, but for now we're keeping things as usual since it's so close to the actual submissions process.
1 - WHAT SNIPPETS ARE: Basically, what the submission are are three sections of your fics, between 500 and 1500 words (please make sure you hit the minimum, and if you go a little over the maximum that's fine) each that best represent sections you would like to have made into art. This is just in case your artist can't read your whole fic.
2 - WHAT WILL BE INCLUDED ON THE FORM: The snippets are only part of the form. Each fic will have a header that will be posted for the artists to choose from (we couldn't include snippets in the posts because Dreamwidth has post word limits and I'd need to make, like, ten posts to host all the pieces and the snippets; we had 227 responses to check in #2 so I'm pretty sure I'll have to make multiple posts this round for all the art, and the fewer I have to make the less confusing it is for artists). It will have the title, the rating, AO3 content warnings, a space for other warnings (both serious and fun), a summary and any authors notes you include for the artists to be aware of.
3 - HOW ART CLAIMS WORK EXACTLY: When I post the list of headers, they're listed first alphabetically by fandom (numbers first, then A - Z, then symbols), and then in each fandom alphabetically by title. Each header is given a number that the artists will submit in a form as their choice in fic.
Normally it's done with 1 choice in round 1, 2 choices in round 2, 3 choices in round 3 and as many more as an artist can handle in round 4, with each round lasting a week. We may switch it up a little this round because we're looking at having twice as many works as last year, so artists could conceivably pick 2 choices in round 1, 3 in round 2, and as many as they can handle in a two week long round 3.
Once an artist has chosen their fic(s), I double check that it's still available (fics are claimed on a first come, first served basis) and send an email to the author with the artist's name and email address, and I also send an email to the artist with the author's name, email address and the snippets.
If an artist reads the snippets and decides they can't do the story, I but the fic back into claims and send the author an email letting them know. This happens very rarely during art claims; usually it's between claiming and posting when artists let us know they're unable to complete the work. In that case, I will make a cover and a wallpaper for the fic.
Any fics left unclaimed at the end of claim rounds is offered a digital fic cover and wallpaper from Mod Ragna, no matter the fandom or rating (please note that I will try to fins someone else who can do non-con/dubcon fics, as they are triggering to me...I had an instance a few rounds back where it wasn't warned for and let's just say I had a bad week after I read the fic). I may bring back my form that users fill out with favorite colors, patterns, images they want used, etc. as I'm expecting quite a few more fics to make art for this round.
Hopefully that helps explain the process a little more. If you have any other questions, ask in the "mod questions" channel in Discord, send an ask on Tumblr or send the mods an email.