Sometimes a client has a strong story but they don't know exactly what they want for the visual look of their game or movie. Enter the ChanMan.
In this video we see Jason go through a broad range of stylistic iterations based on the same lead male character. The client can then use these ideas and move forward with a much clearer visual direction. This gets to the heart of concept art, and the more an artist is able to work in a variety of different styles the more he/she will be able to help a client, and get paid, and then have kids, or maybe a fast car.