You either choose this method of passing the evening because you are in each other's confidence, and have secret affairs to discuss, or because you are conscious that your figures appear to the greatest advantage in walking; if the first, I would be completely in your way, and if the second, I can admire you much better as I sit by the fire."
What does Mr.Darcy mean by this? Like the beginning bits on why Miss Bingley and Elizabeth are walking around the room?