Unlike with fantasy and sci-fi films which by their very nature have some amazing visuals to draw from, the dilemma that marketing people face when trying to promote a comedy is how to convey the concept of the movie with one simple visual. Mostly studios opt for the head shot route and rely on star power and recognisability of the actors to sell the movie, and on occasion they even get them to make a funny face (so that you know it's a comedy).
Here's such an example with The Dilemma movie billboard, featuring Vince Vaughn and Kevin James, snapped along L.A.'s Highland Avenue near Lexington Avenue on December 24, 2010.
