I think that it is only get-away-with-able (!) if you are under 25, size 10 or under and have self supporting (and smallish) boobs. Anything other than that and it would look a bit slapperish (sorry, but you asked!).
I do think it looks like a nightie on the model but presumable she will be at least 5' 8", and probably taller, so it will be a bit longer on you. I think its the length that makes it look nightie-ish, so if you are 5' 6" or below I think it would be ok.