Here is another great post on the topic of mormon modesty messaging.
The boys are treated has full human beings who can be trusted to make their own decisions about modesty. The girls, though, are given a list of rules, as though they are children. On top of that, almost all the language used in teaching the concept of modesty focuses on sexual consequences, and places the emphasis on the girls maintaining their “purity” so they can attract a man who values their “purity,” as expressed by their outward choice of clothing. The boys are admonished to look for women who dress modestly — a woman who would never be a siren.