The LA Times published the photo, which has Stiller holding a skateboard...on what appears to be the set of "Oblivion?" Needless to say 'Walter Mitty', in the original story and adaptation, did not appear to have obvious scope to move in an apocalyptic direction. The film's synopsis says it follows a mild-mannered photo manager at LIFE magazine who is walked all over by his colleagues and friends, and finds escape through heroic daydreams, where he can live any kind of life he chooses -- unfortunately, his idle thoughts end up causing him even more strife than when he's back in reality.
The production features a solid roster of supporting talent including Kristen Wiig, Adam Scott, Patton Oswalt, Shirley MacLaine and Kathryn Hahn. We're curious, but also realize this could just end up as "Night At The Museum" in a different guise. Any guesses what might going on here?