In the tradition of Disney’s Fantasia, it’s visual interpretation of a piece of music, in this case fairly free-form and constantly changing and morphing.
It gets most interesting about 2 minutes in, when Schwizgebel starts to play games with the structure of architectural interiors and related elements.
Schwizgebel plays some similar games with perspective and “camera angle” in L’homme sans ombre (“The man without a shadow”, bottom two frames above), a longer (10 minute) animated short about a man who makes a Faustian deal to trade his shadow for wealth.
Both films are wordless. The animation throughout has a rough, hand-painted look of gouache or pastel, though it may be oil, in a technique known as “paint-on-glass animation“.
I did not find a dedicated site for Schwizgebel, but you can find more of his films with a Google video search.