Griet sees Vermeer's clean hands. What does this contrast with? What could it signify?

Vermeer's clean hands contrast with Pieter's. Pieter always has blood under his nails, something Griet finds repulsive. She likes the cleanliness of Vermeer's hands. Hands are significant to Griet because they represent who she was. Before she took word as a maid, she had beautiful hands. Afterward, her hands became cracked and hardened, as did Griet.