Jimmy looked a little more like Tim Allen in the movie The Santa Clause than Kenny Rogers, but...that is kinda what Kenny Rogers looks like.
If you watch the original performance, you'll see just how well they got it down. Even the background of the stage is on point.
Jimmy Fallon is a self-proclaimed fan of country music, and is friends with Blake Shelton. Fallon has even been very vocal about the fact that he drives a truck. Even though he lives in New York City, where most people don't own cars.