Wouldn't be hard to get the bike off the ground. We have all experienced it trying to top out or bikes, your going so fast you create lift from wind passing under,over,through your fairings and the rest of your bike, all it would take is the smallest bump on the road and you would be air born.
Actually, that's a pic of some very serious wheel hop....the engine torque winds up the chassis and you get a little slip and the chassis unloads, launching that bad boy off the ground, then it comes back down, reloads, retorques, and does it again...looks like chatter when it happens. That's how riders get into serious trouble at the strip....the worst thing you can do is let off 'cause the reverse torque will twist you off the line and get you sideways...
not sure how it happens honestly, but ive seen other pics like this. thats as high as ive seen em get. maybe the shock to the drivetrain when he bangs 2nd gear causes it, not sure. the track is nowhere near bumpy enough that close to the starting line to cause the bike to jump like that either, so idk
oh, and most streetbike guys wear sidi boots with the metal around the toes, because they drag their feet thru 1st and most of 2nd gear. this guy looks like hes wearing some simpson boots or somethin, they look like the ones the pro stock bike guys/girls wear. dont need a moto gp style boot in drag racing imo.