"Chewing scenery" is an expression that's often used to describe actors who are too theatrical and over-act their roles, often with exaggerated movements and grandiose facial expressions. However, there are many other synonyms that can be used to describe this type of acting style. Some of these synonyms include "hamming it up," "overplaying the role," "being too melodramatic," "showboating," "playing to the gallery," and "scene-stealing." Although these phrases all describe the same style of acting, they each offer a slightly different perspective on the performer's behavior, from the performer who is simply too enthusiastic to the one who is deliberately seeking attention.