WARNING! SPOILERS BELOW! YOU HAVE BEEN WARNED!
Supposedly this film is a throwback to the very first one— Kyle Reese is sent back in time to 1984 to save Sarah Connor, but when he arrives he finds the timeline has been drastically altered.
Let's take a closer look at that poster, shall we? As is required these days, it's made from disparate images of the various actors, none of whom were in the studio at the same time, that have been crudely Photoshopped into something vaguely resembling a design.
See the figure in the center? That's actor Jason Clarke, who's playing John Connor in this film. It appears that his flesh is being burned away while he stoically strikes a dramatic pose. So I guess in this film, John Connor, the leader of the human rebellion against SkyNet, is actually one of the very same robots he's trying to destroy.
I assume this is supposed to be the movie's brain-melting plot twist. So why the hell would they broadcast it on the goddamned poster? I don't get it. The various Terminator films have already traveled some pretty well-worn ground, so you think they'd jealously guard any surprises like they were precious jewels.
It's bad enough that modern trailers are basically two minute versions of their films and give everything away— now you have to avert your eyes in the lobby lest the posters spoil every surprise for you.
Thank Thor films like Psycho, Chinatown, The Empire Strikes Back, Fight Club or The Sixth Sense weren't filmed today, or their twists would no doubt be tag lines on their respective posters.