What is the reason behind seasoning "from a distance"?
Looking at the Scallop-and-peas video, it just looks like the chef is trying to sprinkle seasoning evenly onto a relatively small area of food. If you rain seasoning down from a distance it is less likely to land unevenly than if you shake some on at close range. Imagine spray-painting a wall: for even coverage, you gotta stand back.

In the case of the Turkish meat-chef, it is because it looks cool. Notice his theatrical posture.