Woman using iPhone as a ...

Back in graduate school, a friend, "A," joked about a difference between men and women. 

He said that men will stop to look at themselves when they see a mirror.
Women, on the other hand, will check themselves out at anything that has a reflective surface :)

Updating it for the couple of decades that have gone by ... I saw a young woman--maybe a college student--using the iPhone's front-facing camera feature to look at herself and adjust her her hair and lipstick.  The iPhone now becomes a vanity case mirror :)