Lulu Moss says of Janie, "She sits high, but she looks low" (Hurston 3.) What does this mean?

The women were referring to Janie's comportment and dress. They were jealous of her money, and the fact she was being courted by a young man.

“She ain’t even worth talkin’ after,” Lulu Moss drawled through her nose. “She sits high, but she looks low. Dat’s what Ah say ’bout dese ole women runnin’ after young boys.”