[Andi Ramsay]

As far as I can tell most of his work is in-camera, not in post.
Using one of the several available multi-image filters across the front of the lens, the rotation would be achieved manually just by twisting the filter in its holder.
According to what I could find about the director, he opted for shooting vintage glass, and a lot of the visual style is old school (using multiple windows to achieve that layered ghostly shot of the artist, etc.)