Hyperbole and Understatement
It could be argued that humor in general functions through two specific tropes: hyperbole and understatement. The clown is funny because his hammer is comically large and his car is comically small, and the New York sophisticate gets laughs by using the most mundane language to describe the most outrageous behavior of fellow urbanites.
Ian Bogost has spent some time considering the rhetorical appeals of the video Average Athlete vs Olympic Athlete. As he points out, much of the humor comes from the fact that the two protagonists attempting athletic feats aren't lazy slobs but are rather fit and active guys in their average jock prime. It's the combination of understatement and hyperbole that makes for chuckles as the split screen shows the Olympians going so much faster and farther than the regular athletes, often by a factor of two or three.