First, thanks for a great article.
As I read it, the idea is that an "average" (180cm) person's shadow hits the ellipse at the right time if they stand on the right date.
Just to confirm, this is different to a "traditional" sundial where it is the edge of the gonome that casts the shadow. In an Analemmatic it is the top of the (vertical) pointer that should intersect with the ellipse?
I ask because I want to use this to make a dial with a fixed pointer (the top will be a literal point), but curved hour lines so that given the date one can tell the time.