Meet the Mona Lisa of the Prado, the earliest known copy of Da Vinci’s best portrait. Similarity in the undersketch of the painting indicates that this was very likely painted concurrently with the original Mona Lisa, by a student of Da Vinci.
There is much controversy in the art world over the question of whether or not to clean the fragile Mona Lisa, but her sister has been restored and some fairly odd later alterations removed to show the original vibrant colors and lighting. Some details, such as the sheerness of her shawl and the pattern on the neckline of her dress, have become utterly obscured in the original, but in the restored copy they’re perfectly clear.
It blows my mind a little bit to look at these two sisters side-by-side and imagine how much vivid detail could be hiding in the Mona Lisa under 500 years of rotten varnish.