The Paint-Off is an enactment of positive absurdity.
In the Paint-Off, two small but world-wide and growing subcultures come together in one event to watch members from their group do something they love doing for no good reason other than because it is fun.
The first of the subcultures is the contemporary fine art subculture, sometimes called the "art world". Members of this subculture highly value originality and creativity but also enjoy self-analysis and self-critique far more than most people. These proclivities have led to the creation of works of "art" that have been interpreted as various highly creative and original critiques of the possibility of both originality and creativity –– just to name one obvious and delightfully convoluted example.
Painters are only one retrograde subset of this subculture which also includes people whose mediums are ideas, events, sheet rock, bottle caps, beds, and videos. Even under the best circumstances, fewer than 1 in 1000 who try will go on to earn a living from making "art". That doesn't stop would-be artists from going to school for years and incurring great debt to earn degrees at very expensive schools (when they don't drop out and start rock bands).
People who are "famous" in the art world, like Jasper Johns, or Paul McCarthy are almost entirely unknown to general public, and art world magazines like "Frieze" have circulations that would be rounding errors for main-stream magazines. This subculture generally enjoys novelty and will show up at an event just to see something they've never seen before. You may find them drinking beers together talking and enjoying the "meaning" of things that most people would never expect could "mean" anything at all, or finding humor and delight in situations most people would consider at best merely strange and at worst disturbing and threatening. Portrayal of artists on popular television shows are rarely realistic and often present only the most outlandish aspects of the subculture.
The second subculture is the "furries" otherwise known as the "fury fandom". Memebers of this subculture are fascinated by anthropomorphism in all parts of culture from the Disney (fox) Robin Hood to the San Diego Chicken.
The fandom values originality and creativity very highly. Much of the fandom centers around creative production and conventions are filled with artists selling paintings and drawings, plushies, sculptures, comic books, ears, tails, etc.
Fursuiters are some of the most dedicated members of the fandom, spending many hundreds or several thousands of dollars to have a full-body anthropomorphic animal suit professionally made for them or taking the time and energy to learn how to make their own suit.They will ware the suits to furry events or on the street just for fun, an activity called "fursuiting". Fursuiters get a special kick out of fursuiting in situations where one would ordinarily not expect to see them, like at an artfair.
The fandom has its own websites, and publications and more than 20 annual conventions all around the world. Some suit makers like LatinVixen and White Wolf are known far and wide throughout the fandom for their artistry although outside this subculture they are entirely unknown. Although the sexual fetish side of the subculture is just one part among many, it is the part that has been most widely publicized in the popular media.
In the Paint-Off several painters from the artist community pair off with several fursuiters from the furry fandom in spectacular mock-competition to create portraits under the gun of an arbitrary time limit while drinking unlimited quantities of beer and enjoying themselves immensely before a live audience.
If you'd like to read more there is further description in this entry on my livejournal and this entry on my blog.