Following his sensational recent exhibition at the National Gallery in London and the revelation of a newly authenticated painting, the “Salvator Mundi,” there comes a development that is yet more startling: a second Mona Lisa. Nobody is claiming that this picture, which belongs to the Prado in Madrid, was actually painted by the great man himself. After cleaning and technical examination, sponsored by the Fundacion Iberdrola, it turned out to be something almost as important and intriguing -- a version painted at the same time as the original, in Leonardo’s studio. Previously, the Madrid picture, which has been in Spain since the 17th century, was thought to be just a later copy. Conservators have discovered that it was painted on walnut in the distinctive manner of Leonardo’s studio. When old over-paint was removed, a landscape closely resembling the one in the Louvre painting was revealed. Most tellingly, infrared examination discovered similar changes beneath the surfaces of the two pictures. In other words, it seems the Madrid picture was created in parallel with the Paris one, in Leonardo’s studio, probably by one of his assistants such as Salai or Francesco Melzi. Murky Pool Consequently, this new “Mona Lisa” -- currently on view at the Prado (through March 23) and soon to go on show at the Louvre (March 29-June 25) -- probably gives a better idea of what the picture looked like when just finished, particularly in terms of color, than the actual masterpiece now does. There have been complaints since the 17th century that the “Mona Lisa” was so obscured by discolored varnish that it was hard to make it out. Nowadays, the sitter seems to be seen through a green-brown filter as if she were at the bottom of a dirty swimming pool. The Louvre’s “The Virgin and Child With St. Anne” by Leonardo now has been cleaned, despite controversy, and the refreshed or -- critics may claim -- over-bright picture will be the centerpiece of the Louvre show. It would be a bold museum director, though, who ordered the cleaning of the Mona Lisa. In contrast, the Madrid version of the painting has the “rosy and pearly tints” described by the 16th-century art historian Giorgio Vasari. She even has delicately plucked eyebrows, singled out for special praise by Vasari, although no trace of eyebrow can be found on the picture in the Louvre. Twin Monas Why produce two Mona Lisas, one a deluxe version entirely from the master’s brush, and one not? Since a scholar at the University of Heidelberg found a manuscript note from 1503, mentioning a Leonardo painting of “the countenance of Lisa del Giocondo,” the sitter has been known for certain. Previously, the question of her identity was confused by a description of Leonardo showing the picture to a visitor in 1517, and -- apparently -- describing it as “a certain Florentine lady done at the instigation of the late Magnifico Giuliano de’ Medici.” This was puzzling because Lisa del Giocondo, nee Gherardini, was married to a Florentine merchant named Francesco del Giocondo. So why would Giuliano de Medici (1479-1516), third son of Lorenzo the Magnificent, want a picture of her? What if, as Charles Nicholl suggested in his biography of Leonardo, the lady had two admirers: her husband and a wealthy, exiled aristocrat? Giuliano and Lisa were both born in 1479, and belonged to the same elite Florentine circles. And what if the picture now in Madrid was in Florence during the 16th century, and seen by Vasari? That’s all speculation, of course, yet with Leonardo it’s always hard to resist.