Honestly - Photo's strike me as "pinched form a modelling site" as do almost all Asian viva street ads.
Like you said the one thing that makes it seem genuine is the offer to video call. Perhaps just bite the bullet and do that? (from a punting phone of course) If the girl in the pictures answers then there's at least a reasonable chance this is genuine.
My gut says that she'll never answer. They're banking on the offer being enough and that most won't bother but just go ahead and book assuming that all is good.