[cabmandone]

Shoot the wall temp where the picture is hanging and report back. Seems you have to have heat transfer from the unconditioned space that is causing condensation in the conditioned space. Does the room feel warmer to you? You might try leaving the door open if there's a door still in place. I have a room that is kind of off on its own that when I enter from the hallway, I can tell is warmer than the hallway I was just in.