What does the author say is remarkable about Pearl and her clothes?

According to the author, it is remarkable that Pearl's clothing so closely emulated the scarlet letter her mother wore as a mark and punishment for her adultery.

But it was a remarkable attribute of this garb, and indeed, of the child's whole appearance, that it irresistibly and inevitably reminded the beholder of the token which Hester Prynne was doomed to wear upon her bosom. It was the scarlet letter in another form: the scarlet letter endowed with life! The mother herself--as if the red ignominy were so deeply scorched into her brain that all her conceptions assumed its form--had carefully wrought out the similitude, lavishing many hours of morbid ingenuity to create an analogy between the object of her affection and the emblem of her guilt and torture.