Unless this is a continuity error (which seems unlikely), the shot on the right doesn't actually immediately follow on from the one on the left. A little game of spot the difference: Rey's staff is attached to the left of her speeder in the left image, but not in the right. Combined with the music and the previous scenes, showing Rey looking behind her is cheekily meant to create a sense of needing a speedy getaway. It's also meant to make you feel like the shots are part of the same scene. But when you notice her staff is gone and you watch it again with that realisation, the speeder doesn't actually look like it's moving very quickly. Short of Rey having her staff hooked to the right side of the speeder instead, it doesn't appear to be present at all. Which ties nicely into the theory that Rey somehow loses her staff and later returns to Jakku in order to find it again. But mostly, I was just surprised it took (me, at least) this long to realise the two consecutive shots in the trailer aren't actually connected. Well played, Disney.