Constant companion.

This is the face of a dog who knows that you're about to ask him if he wants to accompany you to your office for some end-of-the-evening-and-on-into-the-night work on a massive stack of paper you have to hand over to an administrator in the morning.  And he'll do it all for the attention he'll get all the way there, and maybe also a little for the songs you sing to him all day long.