The lab above simulates what happens when a rubber band is placed on a photocopier. The rubber band is stretched, and then pulled down and released so it oscillates, much like the wave in the simulation above. Try hitting the Pause button - that freezes every part of the wave at one instant, so you capture a snapshot of the wave 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 wave at different times. The result is completely different from simply pausing the simulation because the wave goes through many cycles during the scanning process. This is the essence of the rolling shutter effect.

You can modify the wave speed and frequency, and the shutter speed to observe the differences.