Difference from drawing
Leonardo prepared several drawings to draw the apostles.
Some of them still exist in the Windsor Castle collection, That includes Simon and Bartholomew, and Judas.
And another important drawing is the drawing for James Major.
However, this James Major drawing has slightly different characteristics than other drawings.
Other drawings only show the head, but this James Major drawing shows only the upper body.
Other drawings only show the head, but this James Major drawing shows only the upper body. In addition, this James Major drawing is much rougher than other drawings.
This sketch seems to be drawn on a small piece of paper, but is actually drawn on a much larger piece of paper than Simon and Bartholomew.
In the days of Leonardo, paper was still a valuable and expensive.
Furthermore, in order to draw on paper, the surface had to be specially treated and it was not easy to handle.
It is not usually used to simple draw what you come up with like a memo.
I feel that Leonardo did not had enough time for this drawing.
In order to overlay this drawing on the current mural, the angle of the drawing must be turned.
Furthermore, the position of the hand etc. has been greatly changed in the end.