nope, that smear that your seeing is just a single frame that has motion blur. the wings are much higher the frame before it, and that frame has blur to make up for the sudden change in distance. The motion blur itself is nothing more than curved lines that taper, so basically a custom shape that appears for only one frame.
I won't take credit for the wings though, these were provided from s Double Rainboom puppet rig. I merely recolored it for Derpy.