At first glance, the group of them looks a little like a strange tribute to the old Houston Astros or Denver Nuggets logo. But upon closer inspection, we see that they are more than just quirky eye candy. I'll quote them, so you get the whole picture:
Each color is a point range that the team won or lost by in that year. Green to Red bars are wins. Blues are losses... The key [on the right] shows the average share of games won and lost by each 3 point range over the last 5 years of the NBA.
So, with that in mind, we can see at a glance which teams have a history of winning (lots of green and red) and which teams are typically on the losing side (lots of blue). The Knicks (top) and the Spurs (bottom) are the most extreme examples of a good v. bad franchise. Similarly, you can also see which teams are trending up (see: Celtics, Boston), trending down (see: Kings, Sacramento), or are just totally unpredictable (see: Bulls, Chicago). All in all, it's an interesting way to visualize the winning tendencies of teams. Or maybe I'm just totally geeking out since I'm a graphic designer.
Finally, we come to the Hornets map. And for this one, I'll let you make your own extrapolations... enjoy: