A bit of a guided tour:
That's the heartbeat at the beginning, of course. Then as the ultrasound starts, you're seeing him/her feet-on, arms flailing about. Then the little parasite rotates so its head is to the right side of the screen. At about 1:20 the head turns to give you the full alien view, and at 1:40 it's calisthenics time as its rolled over onto it stomach and does a pushup, just to show off.
