Continuity mistake: In the hologram simulation suite, the amount of smoke changes from cut to cut throughout the scene. (00:06:30)
Audio problem: During the conversation in which Holly wants to prove he has an IQ of 6000 (while Lister and the Cat are scrubbing the floor), there is a brief moment where you can see the TV Holly is on (at an angle). You can hear sound coming from him, but his lips aren't moving. (00:16:55)
Answer: It's Queen Victoria, someone any Englishman would recognize, and needed no introduction.