Since this is a play without a narrator, we the audience take on the role of the third-person observer. We're also omniscient observers because we get to hear what characters are thinking when they turn to us and tell us their thoughts, in what are called "asides."
These asides offer up some of the most hilarious moments of the play, because Molière messes with the convention. Other characters actually hear these asides and ask, "Who are you talking to?" This technique is meant to show the audience how ridiculous and unbelievable asides are to begin with. It's not like you can go to a dinner party in real life, talk to someone, then turn to the side and say aloud, "This person is really boring!" You'd be liable to get punched out.