Figure I should preface this with a couple notes; For the humanized versions in this comic, Pegasi simply fly via magical levitation. The more intensely they exert themselves, the larger/more visible magic wings become behind them. Scootaloo, as she has difficulty flying in the show, is sort of disabled in the magic department, and can decrease her weight, but not actually fly at all. She uses this scooter as a crutch, after a fashion, to channel her weaker magic into something usable for flight.  
Worldbuilding ideas I thought were fun/interesting and might be nice to know for the coming pages.