The theater mask in the Snite Museum collection was found in Asia Minor and dates to about 300 CE. Its features are exaggerated and deeply carved, the eyes and mouth wide open and the eyes deeply set. Although little attention is paid to skeletal structure, the face has other pronounced features, such as a strong nose and arched eyebrows. The prominence of facial features on theatre masks was in part so that they could be seen and understood from a distance: some theatres held as many as twenty thousand spectators.

Large holes like those in the eyes and mouth of the Snite piece allowed actors wearing theater masks to see and speak, but the Snite mask was never intended to be worn. There is no provision for securing it to an actor's head--it is flat on the back, not molded to fit a face--and as it is carved from a thick slab of marble, it would have been much too heavy to wear. Actual theater masks were made of lighter materials--wood, cork, or even leather--and covered the entire head, not just the face.

from Rhodes, Eclectic Antiquity: The Classical Collection of the Snite Museum of Art (Notre Dame, 2010)