In Polygraph by Robert Lepage and Marie Brassard, the stage direction allows the reader to perceive the stunning effect of cinematic technique utilized in this stage production. The use of these techniques gives the play a feeling of continuous movement (as with a movie), while also allowing images to be projected that might be impossible to include otherwise because the production is live.
The sense of cinema is introduced at the very beginning with the introduction of slides that "flash" and display the play's title and actors' credits on a wall to the side. This is similar to the form used at the opening of a movie, naming actors, directors, producers, etc. And whereas a movie can show transitions in the editing of the film (fade in or out, for example), it is much more difficult in a play, when a curtain may close or the scene be darkened while stagehands move props. This can interfere with the production's attempt to make the play lifelike. In this case, however, information related to a scene change is also projected on the same wall, providing again a sense of fluidity, and avoiding the choppiness often present with act or scene changes.
In another instance, the body of Lucy rises and the purpose of her appearance is made clear by the projection onto her body: this would be accomplished with special effects in the editing of a movie (particularly with the use of computers), but stage direction here demonstrates how a cinematic technique is mimicked on stage:
...Lucie rises stage left behind the wall, lit by anatomical slide projections: muscles, veins, organs and bones superimposed on her flesh, as though she is transparent.
In this way, the projection ("projection" being at the core of cinematic works) transforms Lucie into the body of a murder victim being discussed by David, as he reads a "pathologist's report."
Light and sound, as used in a movie, also provide the audience with important elements of staging, such as the setting and plot development. In one scene, to transition from a public setting to one more secluded:
A change in light and baffling of sound indicate they are now private.
In a different segment of the play, allowing for a flashback (a tricky sequence to convey on stage), projection is used once again, a visual mechanism to take the audience from the present (Lucie in her dressing room where she plays Hamlet) to David's past in Germany:
The set of the dressing-room disappears simultaneously, and a projection of the Brandenburg Door fills the cyclorama. David [is] in another time...
In creating a sense of continuous movement (by way of cinematic techniques), the plot development and movement—even between the present and the past—are much more easily accomplished, and more create a more realistic experience for the audience, thus making the play's themes more impactful.