It is actually not a revealing dress...but she is so voluptuous, that her bosom is almost bursting out of her dress......for any normal girl, that would not be a revealing dress..
I have a female friend who has awesome tankers, so whenever she wears a black top, the bulge becomes obvious, does it mean that she is revealing?? Definitely not!! And i'am sure most people would not use a sombre ocassion to fluant, isn't it??