Anti-realism in theatre is considering rejecting any form of something realistic.
Examples of anti-realism types are Theatre of surrealism, theatre of Absurd, epic theatre, and theatre of the Oppressed.
It all started in the early 20th century with Konstantin Stanislavski whose method of acting was extremely realistic with realistic characters and situations. On the other side, his students and other people began the anti-realism movement.
Guidelines are important in photography. They make the job of the photographer easier by making composing a photo easier. When the rule of thirds is applied to photographs or film it makes the art more pleasing to the viewers eye.