Click here to reply to @The79thstreetkd
"Leonardo da Vinci was known to sketch a great deal of his work. Like to paint a sketch before they do their work with painting. And you could imagine what we don't know. What did the Mona Lisa look like in its earliest drafts? When he conceptualized it, before he even got to the preliminary sketches that look very close to the end result, what did that look like? So the process of documenting it is fascinating because of the stages that a project goes through before it reaches final form."