Or in general terms, is it's an anon dump site, make a couple tumblr's for incase they do get deleted.
Or
If it's the artists tumblr
Adhere to:
https://staff.tumblr.com/post/55906556378/all-weve-heard-from-a-bunch-of-you-who-areHell, even their staff accepts NSFW, as long as you list your blog as such, there shouldn't be any trouble.
Twitter is about as mainly just to promote the work by keeping status posts frequent, it's not like they can do this with facebook which would ban their accounts. So very few social sites allow NSFW material. (The ones that are family oriented/business)
Well Instagram also is a great place to advertise, but again, NSFW prob isn't allowed there.
If you're talking about photos, yes, tumblr is about one of the few social media sites that will allow it and prob has more work listed on it rather than twitter, with artists posting up sketches more than actual art work. (prob reason why they link their tumblr as well to show you NSFW material)
Why not show us a vote of how many artists prefer twitter over tumblr when presenting (full to almost finished) work?