The cup moved from the mouse to the monitor when Roy asked him to show the picture from the cup.
A possible goof is when Richmond gives Denholm's mother a Cradle of Filth CD, he recommends track 4 and says that it is called "Coffin Fodder". Coffin Fodder is in fact track 9 on the album "Nymphetamine". However The CD Richmond proffers is not identified because it's gift-wrapped, so it's perfectly possible that the CD is a compilation that Richmond has made. There's no explicit identification of the CD as a copy of Nymphetamine.