Something's off about Just Go With It's poster, and it isn't just that Jennifer Aniston's miscast. While it's possible that she picked off the polish on her left thumb before the photoshoot, that doesn't explain why her fingers don't match.
A reader submitted these shots of an ad hanging in the subway. (You'll note some New Yorker has summed up the movie's plot, labeling one lady "EVIL" and the other "ANIS." They're helpful like that.)
On Jen's right hand, which seems to be the less Photoshopped hand, her thumb bends back:
Most of the fingers on her left hand are hidden because she's making a fist, but her thumb is totally straight with a different nail:
Here's a recent paparazzi shot of Jen, in which she's sporting two hitchhiker's thumbs and polish on all 10 fingers:
Based on this evidence, we must conclude that a stunt hand was brought in to fist bump Adam Sandler while Jennifer Aniston was off getting sloshed on margaritas and adopting more children who never seem to materialize. In fact, there's a good chance the two were nowhere to be found at the precise moment that Brooklyn Decker sauntered down the beach while admiring another picture-perfect sunset. Oh Hollywood, we never should have trusted you!