Mary Warren becomes the target of the other girls' hysteria as they mimic her in an attempt to discredit her confession that the “witchcraft” is all made up. Miller uses auditory imagery to illustrate the hysteria and manipulation among the girls in the courtroom:
MARY WARREN, screaming it out at the top of her lungs, and raising her fists: Stop it!!
GIRLS, raising their fists: Stop it!!
Mary Warren, utterly confounded, and becoming overwhelmed by Abigail‘s—and the girls’—utter conviction, starts to whimper, hands half raised, powerless, and all the girls begin whimpering exactly as she does.
Mary is trying to confess—under pressure from Proctor, who hopes it will help—that she and the other girls were making up all of their “reactions” to being “cursed” by witches. In order to discredit her, all of the girls start to imitate her and scream at her, pretending she is putting a spell on them. This synchronized shouting does more than intimidate Mary: it also makes her accusers seem credibly under the influence of something malignant. Mary is utterly railroaded by the mob she’s faced with, and she eventually cracks under the pressure. The girls all know that if one of them confesses they will all be punished. In order to stop this, they turn on her. The sound of their voices raised together is a literal representation of the overwhelming force of peer pressure she feels. It’s a moment that truly shows the mob mentality fueling the witch trials.