The first twenty minutes of any session here are spent not really shooting. We go through wardrobe, I ask what the pictures are for, and you get used to a camera being in the room. Almost nothing from that stretch gets used, and it is the most important part of the day.
What we are waiting for is the face you make when you forget you are being photographed. It shows up about forty minutes in, usually mid-sentence, and it is the one everybody picks from the gallery.