Do you know what the LOTG say about body language? One may think body language is used to explain a decision. But if you look at the Practical Guidelines, you will see otherwise. However, you can use body language to help control the game or show authority.
In the video below, the referee gives a yellow card for persistent offences. He points at several locations on the field where the player has committed fouls. The referee’s gesture was not just to tell people what the reason of the card was. But he was able to show everyone on and around the field that he was in charge. He was keeping track of fouls. Nothing would go unnoticed.
So this may be a small gesture but is a meaningful one to help maintain control of the game.