[m1el]

It's an artifact of the camera. The camera shutter is long enough that it averages the images over 33ms. At some point in the video you can see that a high speed camera can see the correct display.

[hinkley]

In the high speed you can see that they are distinct but you can see the rollover. Maybe mark V could tighten that up.

[signal-intel]

At the 7 minute mark the industrial 14k FPS camera shows essentially zero rollover. The earlier rollover does appear to be an artifact of the cheap consumer grade high speed camera used.