Outside the jail what does scout's childish attempt at conversation accomplish?

Well Atticus was about to get jumped and Atticus told Jem, Scout, and Dill to go home. Jem refused, and Scout noticed one of the 4 men who was Mr.Cunningham.(Mr.Cunningham is the father of Walter Cunningham which is Scouts classmate) Scout toldMr.Cunningham to say hey to Walter for her, and he noticed what he was doing, and disbanded the mob so he doesn't commit a lynch or hurt anyone in front of his son's friend.