The crew were given a uniforms from Trek II onward that cleverly obscured the steadily expanding waist-lines that most of them were dealing with. Nichelle was not obese but she was chunkier than she was in TOS (and even TMP) and definitely not in the sort of shape you'd want to be for a strip-tease. This is probably why, as they filmed the scene, they tried to hide her middle and focus on flashing her legs. I also think it's no particular badge of honor for a woman to be put into a strip-tease scene whether they can carry it off or not. It's objectification. Exactly. Uhura as a character was much better served when she threatened the transporter operator in Trek III. The strip-tease is a low-brow Looney Tunes way of having the characters try to get out of a jam. It's just bad writing.