Interesting take on Si. I also remember reading (I think from Jung) that many visual artists are dominant Si types.
Well, coming from classic Galen temperament, the Melancholy is always said to be the "artistic" one. And the purest Melancholy is the ISTJ.
This made it completely confusing when I first encountered the Keirsey system, and "the Artisan" was said to be the [totally opposite] Sanguine!
I guess, it's since "artisan" means "crafter" (not necessarily what we think of as a "fine artist"), and this was to convey their skill with the physical senses. Like ESFP's being good dancers (which would be compatible with the classic theory's profiles of Sanguines). The type of "artists" that theory is talking about are the more contemplative arts, such as picture painting and music. These are probably common to the ISTP, who is both Melancholy and Sanguine (IST+SP).
The ISTJ (such as my father, who was a graphic artist on the side when I was young), also seems to be into that, and is probably good at images done from memory. He did not have to set up an object and copy it to the drawing board; he just drew images of people (including himself) or whatever else that came to mind.
It seems in type theory, the ISFP is the one associated with drawing and such, and this is supposed to be the product of Fi+Se. But the ISTJ has Fi in the tertiary (child-like "relief") position, and coupled with the dominant Si, this makes them extremely good artists. This I have not seen covered in type theory, however.