What was the point of that?
The only reason you'd make a Tenacious D animation would be if you had something else to add to the song or original music video, but you didn't. The flash coasted along on the greatness of Tenacious D, which is why there were points in the animation when you didn't know what to do so you put writing on a sign and had some guy eat it. Those were the parts of the song where you showed your true horrifying colours! Out! The power of Dio compells ye!
Actually I liked the mouth animation, it was really smooth, and the frame by frame of them turning towards each other was nice, but the rest was a fairly standard affair.