Visible crew/equipment: When Lister steps back inside the observation room after Rimmer leaves, a stage light can be seen reflected in the window-like light fixture on the wall. It can't be a light on the ship as none of the lighting on Red Dwarf is in the shape of the light seen in the reflection. (00:14:05)
Visible crew/equipment: When Lister is putting the chicken vindaloo on the table, a stage light is visible on the left hand side of the screen. (00:11:50)
Visible crew/equipment: In the Captain's Office, when Rimmer says "That is not true. We played the joke on Mr. Ackerman, sir", a stage light is reflected on the object behind him and Lister. (00:01:05)
Visible crew/equipment: When Lister and the Cat are walking through the corridor on the ship, the top of the set is visible through the transparent ceiling. (00:03:55)
Answer: It's Queen Victoria, someone any Englishman would recognize, and needed no introduction.