It has the quick and dirty, slightly amateurish look of artwork you see on the cover of genre books, like those by Louis L'Amour, or even The Hardy Boys. That's pretty appropriate in a certain way. My guess is it's real but definitely not an official cinema poster, more for a younger audience...the toy angle makes sense.
There's something weird about Shia's chin and neckline in the poster. Struzan wouldn't let that slide, and besides don't we know for sure he is doing the official posters? Don't worry, we have yet to see the full, official poster.