Because ponies and cool art styles. Two good things put together should make an awesome thing, right? *shot*
Haha in all seriousness, this was just me playing around with styles as I often do. I thought, "Hey, wonder if I can pull off a Sonic Riders coloring style with ponies." This is the result.
Though judging by Twi's expression, I'm not sure how well she thinks it worked out.