When in the "backstage to reality", Amanda and Todd's eyes are Mandelbrot sets, a famous infinite pattern within a pattern from chaos theory, both reflecting the world within a world theme of this series, and also a nod to Douglas Adams, who found them fascinating.
As Ken corners Dirk, he says, "Don't you condescend me, Svlad" - a reference to Dirk Gently's real name in the books: Svlad Cjelli.
Ken's last name is revealed to be "Adams", yet another nod to the late Douglas Adams.