Mona Lisa replicas and reinterpretations
After restoration, the Prado's "Mona Lisa" revealed details covered by previous restorations and layers of varnish.
Furnishings and fabrics were enhanced, as well as landscape and facial features.
It is anticipated that such revelations may offer further insight into Leonardo's original.
Experts at the Louvre reportedly supported the Prado museum's findings.
The Prado replica was subsequently transported to the Louvre in 2012 to be displayed next to "Mona Lisa" as part of a temporary exhibition.
Two nude paintings bearing similarities to Leonardo da Vinci's original were part of a 2009 exhibition of artwork inspired by "Mona Lisa".
Displayed at the Museo Ideale in Leonardo's hometown of Vinci, near Florence, some believe one of the paintings – dating from Leonardo's time – to be the work of Leonardo himself, and it has at times been credited to him.
Other experts theorize the painting, one of at least six known to exist, may be just another copy painted by "followers" of Leonardo.
Scholarly dispute persists as to artist, subject and origin.
The nude in question, discovered behind a wall in a private library, reportedly belonged to an uncle of Napoleon Bonaparte, who owned another of Leonardo's paintings.
Facial features bear only vague resemblance, but landscape, compositional and technical details correspond to those of the "Mona Lisa" known worldwide today.
Lego in popular culture
A 2011 exhibition titled "Da Vinci, The Genius" at the Frazier History Museum in Louisville, Kentucky attracted attention by having a "Brick Art" Mona Lisa replica constructed by Lego artist Brian Korte. 
Lego builders such as Eric Harshbarger have made multiple replicas of Mona Lisa. 
Matching the approximate 21 by 30 inch size (535 x 760+ mm) of Leonardo's original requires upwards of 5,000 standard Lego "bricks", but replicas measuring 6 by 8 feet have been built, requiring more than 30,000 bricks. 
The Little Artists (John Cake and Darren Neave) have created an entire Modern Art collection in Lego form. Their exhibition 'Art Craziest Nation'
was shown at the Walker Art Gallery in Liverpool, UK.