I'd say they think just having your knockers out is 'non-nude', cos that
happens to me! I'm thinking you've maybe got to be stark naked to count as 'nude'?
Ahhhh, you have similar problems to me
Mine goes a little futher though.
If I show both my tits inc nips, it goes through fine. If I'm only showing 1 tit inc nip, it gets marked "NN", even if I'm not wearing a stitch of clothing. I have a pic where my friend has both her tits out, one nip showing, and I'm about to kiss it. That got marked as "NN". Then there's the one of me bent over, no knickers, you can see the pussy lips peeking through. That got "NN" added.
BUT. I also have pics wear I am CLEARLY "NN", but they don't get marked as such. I have pics where I'm wearing a bra and trousers, and they aren't marked. One in my lingerie, that's not marked. My face pic, where I'm wearing a top! That's not marked.
So I query with AW, and they say their decision is final. But it's so annoying when I read things on UKP etc where guys may not want to pay for "NN" pics (fair enough!), and the AW "NN" rules aren't applied consistently. Many guys may not realise "Non-Nude" could actually mean you can see the bum crack or nipples and while maybe not TOTALLY nude, there is SOME nudity.
Just my rant du jour