What is strange about the white man standing next to the Indian?

Hester sees that one shoulder is higher than the other. She recognizes something very familiar about the man, and clutches her infant close.

"Although, by a seemingly careless arrangement of his heterogeneous garb, he had endeavoured to conceal or abate the peculiarity, it was sufficiently evident to Hester Prynne that one of this man’s shoulders rose higher than the other."