Structurally unremarkable and noticeably unfinished, Da Vinci's most
famous masterpiece has intrigued experts and laymen alike. One can
spend hours gazing at the mysterious woman, wondering where she is
looking, why she is smiling and, perhaps most perplexing, what is it
about her that captures our attention and imagination more
compellingly than any other portrait.
Let's face it: something about her face grabs hold of us and will not
let go.
The rest.............................
http://www.jewishworldreview.com/1109/goldson_smile.php3
David