MONA LISA'S ALLURING GRIN OF MONA LISA

The enigmatic smile of her visage has captivated viewers for centuries. Is she happy? Sad? Perhaps a mixture of both? The subtle tilt of her lips begs endless interpretation. Theories abound, ranging from psychological insight to pure happenstance. Others contend that her smile unlocks a secret of Leonardo da Vinci's own complex personality, in sta