When you first enter the Presence of the Obama, is is customary to bow or curtsy.
Men: When bowing, bending at the neck is not sufficient. With your hands at your side, bend forward at the waist a sufficient distance that a straight-ahead look will cause you to see the ground or, preferably, the Obama's shoes.
Ladies: A proper curtsy requires that a lady turn her legs outward and bend, then straighten her knees while lowering and raising her gaze in time with the body's movement.
