 In 2004, when the first photographs of the new series' TARDIS prop were revealed, there was a vigorous discussion of the box's dimensions on the Outpost Gallifrey "Doctor Who" discussion forum, in which some fans complained that the prop's windows were too big.Moffat has confirmed that this line is an in-joke aimed at the Outpost Gallifrey forum.Moffat joked that "since I was a kid, I've been thinking of "Doctor Who" monsters, just now when I do, it costs the art department […] a lot of money".