DrChef how can this happen?
I vaguely remember there being an open issue for this a while back, but I could be remembering wrong.
Either way, this would almost certainly be an upstream issue, and not a surprising one. AOSP has a lot of weird bugs when it comes to profiles. Profiles cannot access other profiles' data. I'm not sure how backgrounds/wallpapers work in this case.
DrChef Can this happen because both profiles can access the file system to store images from the camera?
No.
DrChef Just wanted to make sure this is no profile separation bug.
There are bugs, but I don't know of any bugs that make data accessible across profiles. Remember that profiles have different encryption keys. Even if one profile could access another's data, the data would essentially be gibberish to it.