Wow, I can’t wait to see this split up into four separate images of bending!
The upper left quadrant features Aang, airbending. The upper right quadrant features Zuko firebending. The lower left quadrant features Katara waterbending, and Sokka standing beside her. And the lower right quadrant features a mystery earthbender, who is potentially Bumi!
See a larger version at Last Airbender Fans