Inference doesn't run on the RPi Zero. It runs on the VisionBonnet board which has a Movidius VPU tensor co-processor on it. RPi is just for handling the LEDs,

Inference doesn't run on the RPi Zero. It runs on the VisionBonnet board which has a Movidius VPU tensor co-processor on it. RPi is just for handling the LEDs, buzzers and buttons. For training a model with custom datasets, you are correct - something bigger's needed.