The gloss optimizer is found in the newest Epson printer(s) which use
pigmented inks. I do not believe Canon has yet sold pigmented ink for
their printers. Pigmented inks, by their very nature, have solid
material in them which doesn't absorb as well into the surface of
papers. Dye inks are mainly carrier and molecular color, so the color
components are very small and very thin and smooth. They either sit
very evenly on top of the paper, or get absorbed and integrated into
the paper,. leaving the surface of a very glossy paper surface very
glossy.
Pigmented inks tend to have a rougher and thicker layer, and so a
"gloss optimizer" coats the surface to make it shinier. Also, the
papers that readily handle pigmented ink tend to be less glossy.