Adjusting yoyo?

In the slack trapeze video Andre does a trick in which he takes the yo-yo in his hand and it looks like a sidewinder. What’s is the name of this trick and what is it’s purpose?

Thanks ;D

I don’t know what its called but its for unresponsive string tension.

Check out the string tension videos! It’ll clear it all up. Twisty strings = bad for business.