Why does Caroline request that Elizabeth take a "turn about the room"?

Caroline wishes for Mr. Darcy to notice her.

Miss Bingley made no answer; and soon afterwards got up and walked about the room. She walked towards and away from him; she walked past her sister who patted her hand. Her figure was elegant, and she walked well; - but Darcy, at whom it was all aimed, was still inflexibly studious.