I have Global Entry so when I go through US Customs I just go to the kiosk, scan my passport, answer the questions on the screen, get my printout and move on.
Today, the kiosk asked me to stand in front of the camera first. It took my picture and spit out the printout. No questions no passport scan nothing, just my picture. On the printout was my name, passport number, flight info etc. It was super fast and easy but a little weird too. The gubment knows who you are for sure.