Sentence:  This is a flat, unnecessary, and strangely disturbing denial of the <WSD>fourth-wall</WSD> convention, that unwritten agreement between playwright and playgoer whereby you think of yourself at the theatre as a privileged, exonerated, comfortably seated eavesdropper. 
Meaning of the word marked with <WSD> tags:  The imaginary invisible wall at the front of the stage in a proscenium theatre, through which the audience sees the action in the world of the play.