You don't need to do silly head movements. You could send the other person and email with a password, or a text, or a signal message or ask where you last had a

You don't need to do silly head movements. You could send the other person and email with a password, or a text, or a signal message or ask where you last had a drink together or... If you are concerned that all methods of communications are compromised you wouldn't suddenly trust zoom if they do some silly head movement.