Whip the pointer across the tile and its speed tears a local vortex into the drifting dust: the swirl spins up then unwinds, and a fast gesture leaves a short trail of up to three dying eddies. Fine debris streaks shear tangentially inside each vortex so the spin reads violently, over a parallax fbm cloud. Untouched, a virtual cursor throws slashes and loops on its own, each leaving an eddy to spin down.