When I looked at a woman's outer labia, I couldn't figure out what I was looking at. Each specimen looked so different.
Then I learned (in my fifties) by looking at the many photos on the internet, that that's it! Each one looks different because each one is unique. It marks her as an individual. It's like markings on the tail fin - the fluke - of a whale. Each one marks each whale as an individual.
World As Monkey Island