On Sunday, Dove posted an ad that aims to do more than sell you a bar of soap. In three minutes, the spot teaches a crucial lesson about the way we see ourselves as compared to how others see us.

For the experiment, a former forensic sketch artist spoke with a number of women from behind a curtain, asking each to describe their appearance. While sketching, he combed through every detail—from hair length to facial structure, eye color to complexion.

Each partipant had earlier been asked to get to know another. Later, they described their partner's face for a second sketch.

"Women are their own worst beauty critics," Dove says. "Only 4% of women around the world consider themselves beautiful ... we decided to conduct a compelling social experiment that explores how women view their own beauty in contrast to what others see."

Now go buy more soap.