If you've ever taken a film criticism class, you're familiar with the Auteur Theory. At its core, it states that films are a manifestation of the director (or "auteur") and his/her creative vision, and despite all of the other things that go into the making of a film, the director is the primary "auteur." You know, a Tarantino film is a Tarantino film - you just know it when you see it.
As a film lover, this videos makes me so happy. Part of the joy of movies is celebrating famous filmmakers' stylistic peculiarities, and if you get a kick out of Fourgrounds Media's The Auteurs of Christmas - well, good. That means that you've watched enough important films to get the jokes.
Bonus points for the Von Trier segment. That was f'ing perfect.