Visible crew/equipment: When Todhunter asks everyone to stand for the cutting of the cake, a red boom mic can be seen in the top left corner of the screen. (00:12:05)
Visible crew/equipment: Just after Lister hits the toaster, a pair of legs can be seen moving in it's reflection a moment before the scene ends. (00:11:30)
Visible crew/equipment: When both Rimmer and his future echo walk through the door from the captain's office, the edge of the set can be seen. (00:15:09 - 00:16:04)
Visible crew/equipment: When talkie toaster says 'light speed' a crew member can be seen in its reflection wearing a yellow t-shirt and jeans. (00:17:35)
Visible crew/equipment: Just before Rimmer sends his 'Internal Memo' Lister is standing next to his fish tank in the sleeping quarters. In the relection of the glass you can see pages being looked through by a member of the crew. (00:23:15)
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)
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 talkie Toaster says, 'I toast, therefore I am.', you can see the legs of a crew member moving in the reflection of the toaster. (00:04:40 - 00:11:50)
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)
Confidence and Paranoia - S1-E5
Visible crew/equipment: When Rimmer says there was nothing wrong with his casual clothes, a boom mic shadow can be seen moving at the top of the screen. (00:06:10)
Confidence and Paranoia - S1-E5
Visible crew/equipment: In the medi-bay, when Rimmer says, "How about an anal reading?" a yellow microphone appears above his head. (You can see this if you watch the dvd on your pc, as some tv's can cut off the edge of the picture). (00:11:00)
Confidence and Paranoia - S1-E5
Visible crew/equipment: When the skutters try to move Lister in the Medi-bay, you can see the cable which pulls Lister's chair in the bottom right of the screen. (00:12:40)
Visible crew/equipment: When the crew are in their sleeping quarters, and Rimmer is talking to the others, a blue boom mic can be seen hovering over his head (you can see this if you watch the dvd on your pc, as some tv's can cut off the edge of the picture) (00:03:10)
Visible crew/equipment: When Rimmer is getting in the car on the beach, you can see the cameraman's reflection on the side of it. (00:18:25)
Visible crew/equipment: When the Cat licks Better Than Life's host, there is a shadow of a boom mic at the top of the screen on the wall. (00:19:35)
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