In this photo, the very beautiful and talented Eva Longoria (Tony Parker - what's wrong with you?!) gives us a great example of a classic female sexual display. When a woman preens her hair with her armpit exposed, this is a signal that she is sexually attracted to someone in the immediate vicinity. True preening of any type, is a signal of respect or attraction - however female hair preening with the elbow/arm extended laterally and her armpit exposed - this is a strong (though largely subconscious or edge-of-consciousness gesture) biological signal of female sexuality. Such arm position puts the breasts on display in a prominent fashion while simultaneously exhibiting overall health and confidence. The exposed armpits also allow releasing of pheromones and/or pheromone-like substances. These chemical messengers stimulate potential lovers' olfactory systems to powerfully and subliminally attract them. Be careful not to confuse any "hair touching" in an over-generalized fashion - for there are, to the untrained eye, somewhat similar gestures with essentially opposite meanings.