I wouldn't be surprised if they were a public opinion piece. They release the photos and gauge what people think. If people love them, then hey, no change. If people hate then, then oh, we were just making a publicity shot! That's not how he really is!
Because that's just a BS answer. If it was just a publicity shot, the point is to show how you are doing the character. You wouldn't add a bunch of stuff that isn't in the movie. It would be like if they did a publicity shot of affleck as batman, but dressed him up in the sinestro corps suit.