Bogart as a screen writer, and as an observer
This is the 2nd film I know of in which Bogie portrayed a screen writer. Also, I noticed in this that he very much played the role of one who is intently observing the actions of those around him. That fits with a screen writer personality and it also fits with his private eye roles. Most impressive was the way he watched and studied the actions and conversation of others.
Life, every now and then, behaves as though it had seen too many bad movies