Situation: I am sitting on an office chair at the table facing the table while being between two other office chairs and the radiator is behind me.
Alternative situations: Sitting on an office chair while being between two other office chairs, the radiator behind me keeps the area warm. I am sitting on the middle chair, bottom side of the table, my left leg resting on the table in front of me while I crack jokes with my coworker that is sitting to my right side.
Question: What light source is on the wall behind me?