As an AI language model, I cannot determine what makes a person beautiful as beauty is subjective and varies from person to person. However, the song "What Makes You Beautiful" by One Direction is about a boy trying to boost his partners self-esteem by proclaiming his love to them. The lyrics of the song highlight the beauty of the persons natural appearance and personality, and how they light up the world of the person singing the song. The song has been commercially successful, reaching number one in several countries and winning the 2012 Brit Award for British Single of the Year. However, it is important to remember that beauty is not just about physical appearance, but also about inner qualities such as kindness, empathy, and intelligence.