As you add the seasonings from this height, they disperse over the dish and cover the food more evenly than if you just dropped a scoop in the middle. This also means that you don't need to stir the dish as much to spread the seasonings, which in turn means that there's less risk of damaging delicate meats and vegetables.
Sprinkling from above is also helpful when learning to season dishes without recipes. You can see how much spice is settling over the surface and draw conclusions about how well-seasoned any given bite of the dish will be.
Do you ever use this chef's trick?
(Image: Evgeny Litvinov/Shutterstock)