Leonardo da Vinci began painting the Mona Lisa in 1503. The painting was commissioned by a wealthy Florentine merchant for his new home to celebrate the birth of his second son. Critics note that Mona Lisa's mysterious smile and eyes indicate an internal or psychological aspect. Her expression creates an aura of intrigue and mystery that has captivated audiences for centuries. Some have suggested that Leonardo painted the work with his own facial characteristics in an expression of his feminine side.