Richard Sheridan Willis as the Chorus in a 2013
Folger Theatre production of Henry V.
We might suppose that choruses, and characters who serve as choruses, always speak with this kind of courtesy, but two of Shakespeare's actually insult their audiences: the character who delivers the epilogue in Troilus and Cressida says that he will transfer his venereal diseases to the audience's many pimps and prostitutes; and the chorus of 2 Henry IV delivers a prologue implying that the audience is a mob, a "blunt monster with uncounted heads." These speeches implicate their audiences in the vices portrayed in their plays. Troilus and Cressida depicts weakness and corruption, which are well symbolized by V.D., while 2 Henry IV depicts the power of rumor, which spreads through mobs.
Henry V's prologue serves a different purpose: to inspire the audience. Though the Chorus begins by saying that the play's subjects can't be presented in this theater, halfway through his speech he makes a U-turn. The clash of kingdoms can be fully recreated, he says: "two mighty monarchies" and a "perilous narrow ocean" can appear "within the girdle of these walls," and huge armies can battle on this stage—if the spectators use their imaginations. Like Henry rallying his men in his "Once more unto the breach" and "band of brothers" speeches, the Chorus rallies the audience, urging them to marshal their "imaginary forces" (a metaphor that connects their imaginations to the armies at Agincourt). When you see an actor holding a pike, he tells them, visualize a thousand soldiers like him. When you hear an actor talk about horses, "[t]hink . . . that you see them / Printing their proud hooves i'th' receiving earth."