Why is body language significant in the novel, Mrs. Piggle Wiggle?

Body language is a symbol of a person's mood or attitude, and it seen throughout the novel. Mary O'Toole is a girl who begins to talk back to everyone around her until Mrs. Piggle-Wiggle lends Mary a parrot that talks back better than Mary. Mary's stance and the position of her face are symbols of her preparation to talk back. Allen, the little boy who refuses to eat, is slumped on the back of the pony, and his stance is a symbol that he has grown weak from hunger.