All the architecture of the Caligari film seems pasteboard.

The whole thing happens in a cabinet.
It is the most overwhelming contrast to Griffith's Intolerance that could be in any way imagined.

It contains, one may say, all the effects left out of Intolerance.

The word cabinet is a quadruple pun.

Not only does it mean a mystery box and a box holding a somnambulist, but a kind of treasury of tiny twisted thoughts.