Have you seen the movie where she wear a pink dress and go in the pool, her tits are way less "big" and fall naturally, its more the way the pics are made there, remember a pic can be altered so much its possible to see Jessica Alba get a facial cumshot... So pics can altered and most probably in this case she just wear something to make them look bigger and rounder, also on some pic she kind of lift them in a way...
And last thing, i would found that stupid to have a boob job to pass to a B cup to a.... B cup... i mean cmon...