It's when it's overdone. Remember that in the theater the performance should be natural, but extra-daily. We cannot act in the theater while acting in everyday life, as we would see negative action that is the opposite of hyperactive. That is why it is called "theatrical" since theatricality is a midpoint of theatrical performance, where it looks natural, extracytic, but not hyperactive. Overacting occurs in actors who have not yet acquired the necessary technique for the correct control of their energies.
Exaggeration can not only refer to the way an actor works but also to the behavior of a person who is exaggerated in their attitudes and gestures. Overacting is related to hypocrisy that shows a lie and artificiality.
Therefore, overacting also produces mistrust on the part of others who observe attitudes that they consider strange. However, it should be noted that a person can overreact in their way of being without realizing it. That is, it is not positive to judge people based on their appearance.
Anyway; overacting is based on conveying a lot of artificiality in a dialogue or a gesture. It is an exaggerated form of acting in which the actor seems to pretend rather than convey the truth with his role. When an actor overreacts, you realize that he is not comfortable with his character. Film critics can judge an actor's work negatively if they consider that they have been hyperactive, not credible in their role.
