What is significant about Mistress Hibbin's remarks to Hester and Pearl?

Mistress Hibbins comes up to Hester and tells her that she knows Dimmesdale and Hester met in the woods. She indicates that she knows about Dimmesdale having received the badge of sin and knows that he is hiding it. She then says that the Black Man has "a way of ordering matters so that the mark shall be disclosed in open daylight to the eyes of all the world."