The lab above simulates what would happen if a spinning fidget spinner was placed in a photocopier. Try hitting the Pause button - that freezes the fidget spinner at one instant, so you capture a snapshot of the fidget spinner at one time. Hit Play, and start the photocopier scanning - this is what the output of the photocopier looks like because as the copier scans across from left to right, it captures different points on the fidget spinner at different times. The result is completely different from simply pausing the simulation because the fidget spinner can do a few or even many complete cycles during the scanning process. This is the essence of the rolling shutter effect.

You can modify the shutter speed and the spin rate of the fidget spinner and observe the difference.