The analysis of theatre semiotics is a methodology developed by Elaine Aston and George Savona that considers performance as a system of signs that create meanings.
In their book Theatre as a Sign-System, Aston and Savona explain that everything that happens during the performance is a signifier and it is used to express a particular concept either by the director or by the writer. For this reason, a semiotic analysis does not only take account of the text, it also investigates everything else that make the performance.
Those visual signifiers are divided into two categories:
Synthesis, which is everything involving the staging (including costumes, props, sets, lights and venue).
Kinesics, which is every aspect of the space in relation to the actors (including the bodies and movement of the actors).