While there is no telling if this was a) taken at Pinewood Studios in England, b) taken on a set Disney owns in LA, or c) Peter Mayhew in the famous Kashyyyk native suit, but we DO know the gentleman in the photo is Bob Iger the Chairman of Disney. And that it was posted on the official Star Wars Instagram account.
And an update on this from The Daily Dot:
Update: Matt Martin, Manager of Digital Content and Community Relations at LucasFilm, has confirmed on Twitter that a tweet from the official U.K. Star Wars account claiming that the selfie shows the official Chewbacca was suit was actually “speculation.”