I think what he's doing is: (Downpick B, sweep to E, Up Pick E, Downpick E, Up pick E, Sweep back to B ) in a loop. Slowed down it's like a 1,2,3, 1,2,3, rhythm:
It's really fun & easy once your hands are used to it! :giggle: apologies the demo was on acoustic, my fiance is asleep in the next room