With its unnaturally acute angles and Munch-like waviness, you knew that the sets were signifying emotion rather than things, or that emotion (angst) had invaded the things, and bent them under its superior power. And its topic is also emotion—angst made real in delirium. The twist ending makes “mere” psychological reality more real than the sad Foucauldian “reality” of power-knowledge that has cooped these people up together so that they can be recurring canvases for their projections.

The sets, the story, and the psychologizing twist ending have all made Caligari “the first Expressionist film.”

What does that mean? I go on about it a bit here.