Situation: I am sitting on the leftmost part of a couch and there is a lamp on my left within reach.
Alternative situations: I set down on the end of the couch and realize I forgot to get my book off of the table in front of me. I sat down on the couch and grabbed the book on the end table to my left.
Question: Is the backpack on my 11 o'clock direction placed on the chair or the sofa chair?