Isleworth Mona Lisa
According to Leonardo's early biographer Giorgio Vasari, Leonardo had started to paint "Mona Lisa" in 1503, but "left it unfinished". However, a fully finished painting of a "certain Florentine lady" surfaced again in 1517, shortly before Leonardo's death and in his private possession. The latter painting almost certainly is the one that now hangs in the Louvre. Based on this contradiction, supporters of the authenticity of the "Isleworth Mona Lisa" claim it is the unfinished "Mona Lisa", made at least partially by Leonardo, and the Louvre "Mona Lisa" a later version of it, made by Leonardo for his own use.
Speculations about Mona Lisa
The artist Susan Dorothea White has interpreted the masculine proportions of Mona Lisa's cranial architecture in her anatomical artworks "Anatomy of a Smile: Mona's Bones" (2002) and "Mona Masticating" (2006). Lillian Schwartz of Bell Labs suggests that the "Mona Lisa" is actually a self-portrait. She supports this theory with the results of a digital analysis of the facial features of the woman in the painting and those of the famous "Portrait of a Man in Red Chalk". However, the drawing on which Schwartz based the comparison may not be a self-portrait.