Yes. There is a gearbox at the rotor.
Ah, sneaky !
As usual! LOL
And in the days of CRT monitors and flourescent office lights it would give some people horrific headaches.
Latency is a really neat aspect of lighting that, done well, is almost completely invisible. That fall time described, preceeded by a corresponding rise, is aesthetically pleasing or expected is a lot of applications and is artificially simulated. For example, motor vehicle turn indicator LED assbys sometimes introduce a little fade in/out to appear less strobey. You can also often see it in the familiar wigwag during a railroad crossing. Those recreating the hallmark exterior lamps on KITT/Knight Rider replicas have to think about this stuff.
Some devices use slow modulation to represent breathing or sleeping, sort of related.