While there is some truth that Darcy is a great man status-wise and dancing with Lizzy is a compliment, gives consequence to her, Lizzy is skeptical. Lizzy’s thoughts “so great a man” and “amazed at the dignity” concerning Darcy are heavy with irony. Lizzy thinks it odd that a man who thinks so highly of himself and so little of her (Chapter 3) would spend time looking at or dancing with her. I have never read these thoughts as straight-up compliments to Darcy or Lizzy feeling herself unworthy of his attention—just surprise infused with her typical ironic outlook on life. She has reason to be wary of his motives; he has proved himself to have a satirical eye after all. ;D