True story :

Lisa del Giocondo was a member of the Gherardini family of Florence and Tuscany, and the wife of wealthy Florentine silk merchant Francesco del Giocondo. The painting is thought to have been commissioned for their new home, and to celebrate the birth of their second son, Andrea.  

Speciality: 

Leonardo was fascinated by the way light falls on curved surfaces. The gauzy veil, Mona Lisa's hair, the luminescence of her skin – all are created with layers of transparent color, each only a few molecules thick, making the lady's face appear to glow, and giving the painting an ethereal, almost magical quality.