How do the smilers have three faces?

Question

In the Doctor Who episode "The Beast Below", it is logical for the smilers to only have two faces (one on each side).

So how can they have three faces?

Answer 1

Unless the plot ever returns to Starship U.K., this is unlikely to ever be directly answered.

So I will indulge in educated guessing once again. While advanced enough to have what amounts to a giant contained atmosphere and civilization in space, the government of Starship U.K. doesn't seem to have the ability to fold space on a whim. That tells us that there really only should be space for two faces.

So if there can be only two, the face on the back has to be able to be replaced or reconfigured on a rather quick basis. With the sort of ceramic look to the faces, changing them doesn't seem likely. Then again, neither does replacing it so quietly and quickly without anything ever being seen. Since they are at minimum, mobile robots and observer drones, you can say that the technology behind them is far deeper than their look would suggest.

So maybe their design is too. After all, why would you make something that looks like a steampunk ceramic head in a box, something out of an old carnival, if it's much more than that? Well, the theme of the bad guys is intimidation; trying to keep the secrets of Starship U.K. under wraps. I think that extends to the Smilers. Make them look simple, but capable of far more. Make them put people on edge, nervous and a little afraid, so a citizen will think twice about crossing a line. And then if necessary, a lot afraid, with just a cunning little parlor trick.

That the writer or showrunner (curse you Moffat) gets to pull the trick on the audience as well, call it a bank shot.

My answer would be that the solid ceramic isn't actually as solid as seen, that the faces can reconfigure, based on the lack of any face-switching noises or motions seen.