Some of them take photos then do the paintings...
Regardless, AMAZING skill, and worthy of any scholarship or donations.
You have to work with a photo or from a live model or scene.
As said above, I sketch and can tell you that getting the dimensions of everything in the drawing right at the very start is a monstrous undertaking.
And after you get everything where it's supposed to be (in a rough pencil sketch), then the real art begins.
I can't imagine how those sculptors work. That is simply beyond my small brain.
As any artist will tell you, the art in this auction required some very real artistic talent...but the amount of craftsmanship involved (and love of subject) dwarfs the raw talent.
I am going to share this article with friends (mostly collectors). They will be as blown away as I am.