The Observer can be seen in the first club scene, passing from right to left (to the viewer) behind the back of the man on whom the scene is centered.
The Observer can actually be seen twice in the first club, both times passing from right to left behind the male from the opening.
Dr. Boone works under the assumed name of Lubov Pharmaceuticals. In real life, Lubov is the assumed name of a Russian painter whose work centers on science-fiction and fantasy.
"Lubov", as in Lubov Pharmaceuticals, means "Love" in Russian.
The glyphs in this episode spell "Eight".