That's a contented looking GSP and typical behaviour for the main member of the family. A big boofhead.

My GSP definitely thought he was a person and used to talk to us. When I teased him about us not understanding him, everytime he got upset and usually barked at me for being stupid.

I had been told that if you talk to your GSP (or many dogs) a lot they show the sort of behaviour ie understand a lot more words than you might think.

For example, I would ask him - "Is that Christine coming?" and he would run around the corner to look for her car.