That's a good question. The distinction is between generative AI (which takes in a prompt or image and generates every pixel of a new video) and non-generative AI models (e.g. classifiers, segmentation models, and pose estimation models). The second category helps us to infer characteristics about the input drawing, but it doesn't try to 'recreate' anything.

We use non-generative AI models to quickly auto-rig the character when it's uploaded. In a traditional computer graphics animation pipeline this would be done by hand and would be a slow process; we use these models to speed that step up. The resulting animations don't use any AI at all(generative or otherwise).