Reading from left to right, this Men in Black 3 poster features 1960s Agent K, time-hopping agent J and then the Agent K from the here and now.
I hope we get to see a lot more of Josh Brolin in the marketing materials from here on out. I've always enjoyed the "one actor mimicking another" thing, like in Face/Off or when characters get masked-up as one another in the Mission: Impossible movies, and Tommy Lee Jones has got quite a clear manner to pastiche. I'm not saying it will have me rolling in the aisle or anything, it's just something I've always been a bit intrigued by.
Thanks to Cinepop for the poster. I saw it crop up in a few places but theirs was the best quality.