This scene is a classic example of what narrative theorist Northrop Frye called "metalepsis," that is, the intrusion of extradiegetic elements into the world created by a film. When Woody Allen interrupts his conversation with a pedantic media professor to address the camera directly, he violates one of the classic rules of cinematic form; however, when Marshall McLuhan appears in the scene, playing himself, we momentarily experience both McLuhan as McLuhan and Woody Allen as Woody Allen. The effect of metalepsis, according to Frye is to induce in the audience an awareness of the multiple layers of reality and of storytelling that are present in any narrative experience.