Any word on whether pickups count for the whole team? I've been playing the whole DLC with a full four person team, and all together we're at about 6. I think I remember some challenge completion bar popping up when one of them said they picked up a picture.
Edit: Derp. Disregard this. I didn't see the full second page of posts 'till after. x.x
Looking to boost anything I haven't completed. Especially arcade games.