SciFi said:
Photography > People & Portraits > Artistic Nude
Photography > People & Portraits > Fetish Portraits

dA has more tollerance for that large gray area where you can have nudity before you reach the "is it porn?". It just doesn't show up much until you go down the right category path. Tumblr is stating there will only be tollerance for the legal requirement - images depicting breastfeeding for example.
Yeah but actually, DA has been acting strange recently as well, deleting deviations for sexual reasons.

Obviously fetish material is much of what is popular but well, that doesn't always stop them from banning it seemingly at random.

And no they don't allow sex scenes...