Hardware - TomWhitwell/SlowMovie GitHub Wiki
The install guide generically says a Raspberry Pi is needed for setup of the SlowMovie player. While this is true you may see better results depending on the model being used. Below is a general guide based on user experiences.
Raspberry Pi 3 and 4
These will definitely work and will probably offer the best overall performance. It doesn't seem to matter if using the Full Desktop version of the Raspberry Pi OS or the Lite as they will have enough processing power regardless.
Raspberry Pi Zero and Zero W
There are confirmed user reports of these working with SlowMovie. With the smaller form factor they are an attractive option for hiding within a picture frame. The Lite version of Raspberry Pi OS is preferred due to the overhead of the Full Desktop on the smaller device over time. There are also reports of more lock-ups of the EPD drivers on Pi Zero devices. These are due to conditions in the EPD driver code that appear to cause IO issues between Python and the hardware.