Brenda Laurel posits a model of "computers as theatre" in her book of the same name that puts both computer and user on the boards of the stage to act. Each agent has an apparently equivalent amount of power to exercise, and the emphasis is on collaboration. There is no audience in this world; all that exists are the actors who stage a production.
The world in which these actions take place and seem to work--the screen of the computer--appears self-contained, enclosed...what I would call "pure" and "secure" from the distractions and interference that often come from outside theatres, or even from audiences inside theatres.
And yet this model ignores the presence of the box humming underneath or next to that stage of the screen, perhaps because acknowledging that presence undermines the sense of integrity within the secure space of this imaginary theatre. The box, then, is the backstage--its internal operations hidden from view of the actors, but ultimately in control of the technical aspects of this production. Perhaps it is even more than that--the backstage, because it can enable and disable certain actions without our prior knowledge, is the imagined man behind the curtain, the agent that hasn't been accounted for in Laurel's model and can only be imagined by the actors on her stage. But sometimes the backstage demands to be more than imaginary and is revealed on the stage itself--purposefully or by accident.