Implied nudity

Florida's Palm Beach Post publishes a Washington Post-distributed feature, "Should Your Kids See It?". It's a series of movie reviews that addresses all the objectionable elements of movies--whether they have foul language, violence, drug use, etc.; I suppose, so that a parent can make an informed choice about the level of trauma to inflict on his child. The movie reviews often mention "implied nudity" or even just "implied toplessness." Doesn't clothing necessarily imply nudity? I guess the answer is that you can't be nude (in a woman's case anyway) unless there's a nipple; in Vermont, for instance, you are a criminal voyeur only when you get a look at "any portion of the female breast below the top of the areola" (13 Vt. Stat. § 2605).