Visible crew/equipment: When Lister is speaking to Kochanski and realises it is actually Rimmer, Kochanski says "it's Kochanski's body, it's Kochanski's voice" and a red boom mic is visible at the top of the screen. (00:27:45)
Visible crew/equipment: When Lister washes his face in his sleeping quarters, Rimmer is seen off set in the reflection in the fish tank walking past. You can see his uniform and can just make out the H on his forehead. (00:04:40)
Visible crew/equipment: In the flashback scene of Lister and his mates, just after Lister says about brains in jars, a yellow boom mic can be seen at the top of the screen. (00:06:00)
Answer: The cello is a large four-stringed instrument, which, when it is played, stands vertically on the floor between the player's legs (assuming they are seated). If it is to grow as large as the other instuments mentioned will, it would require a rather unseemly lack of femininity to be able to encompass it with the legs.
Rooster of Doom