An odd way to observe the rules of tzniut/modesty (in my opinion)

This is something that I've rarely seen in the Orthodox community, but I've seen it occasionally, and it startles me every time:  a woman wearing a top that covers her elbows but exposes a hint of cleavage.  In what world are a woman's elbows sexier and more enticing to straight men or gay women than a hint of breasts?


(For an example, see the movie "The Women's Balcony," which I recommend--I'll put the spoiler in the first comment.)