Uh.. this is well.. frightening

[I_am_not_mafia]

It may technically just be just a position of the arm but the purpose is the same. To unify identity and pledge allegiance. It's no different to having everyone place their hands on their chest except the hand in the air is more visually striking and effective which is why Americans schools used to insist upon the Bellamy salute. It was only stopped when it became associated with the Nazis yet it is also the Roman salute. This is yet another mechanism that can be used by an authoritarian or fascist government which everyone thinks is normal, especially since Americans are used to having to pledge allegiance in schools.

You could easily have some other alternative, like the fist closed or the forearm extending vertically into the air. The function would be the same.