She has ......stated that her boobs are her favourite part of her body- i don't think it was an accident. Personally, i think you are slightly shocked that vanessa would do such a thing, when actually i don't think vanessa has a problem with it (or many other people either).
Actually, it's her legs that are her favorite part, but she's happy with her boobies.
It could be a case of not realizing the top was that transparent. Camera flashes can make a top more revealing than you realize in normal circumstances. Remember the incidence with John Kerry's daughter??
With that said, I personally see it as more artsy beautiful than graphic porno, but I can also see how the picture could be abused by confused teenies and the V-hating micro-minority.