[hanrelan]

I was wondering the same and this video [1] helped me better understand how the prediction is used. The original paper isn't super clear about this either.

The diffusion process predicts the total noise that was added to the image. But that prediction isn't great and applying it immediately wouldn't result in a good output. So instead, the noise is multiplied by a small epsilon and then subtracted from the noisy image. That process is iterated to get to the final result.

[1]https://www.youtube.com/watch?v=J87hffSMB60