She was bikini-clad in a tiny, tiny bikini, and thus pretty darn close to nude, particularly with her figure, but definitely not nude.
Upton was demonstrating how to do the "Cat Daddy," a dance created for hip-hop track of the same name by The Rej3ctz. After finishing her demo of the "moves," Upton concluded by saying “That's it; that's all you guys need?”
To be clear, YouTube restored the video on Wednesday, after removing it on Tuesday. However, in order to view the video now, you now have to be (or at claim to be) 18 to view it.
Watch the banned video, below.