The Picasso Mystery is
a documentary of Henri Georges Clouzot of which you can see extracts below,
although it is at the origin of a polemic (founded or not, with you to make you your own opinion),
one is struck by :
1 - The dexterity of the artist, the facility with which it draws, although it is not famous
to be a famous draftsman.
2- The order of creation of the elements represented in the drawings. One does not imagine, if one had to even do it us, to be able to compose of the drawings like that and especially in this order.
Picasso starts with the details, then he adds the framework and to final the colour.
Certain details, with final are unobtrusive by the colour, it is enough diverting to tell the truth.
Concerning the polemic one showed Picasso and Clouzot used for documentary play of camera and a system of projection into negative called the space screen of Kahnweiler.
Daniel-Henry Kahnweiler (1884 - 1979) is a writer, collector and of German merchant of art,
promoter of the movement cubist in the years 1910 and 1920.
See the description of the process here