Situation: I am sitting in the office chair typing on the keyboard.
Alternative situations: I am looking at a youtube video on the monitor in front of me sitting comfortably on this office chair, I pushed the chair a little far from the table in front of me so I could have a better look. I sat in the office chair and there was another office chair to my right.
Question: What is the source of light in the room above the table in front of me?