This is a fancy name for using the same thing several times for immersion practice, potentially with very different approaches. For example:
That's a very specific version of The Multipass Method, for you it will almost certainly look different. But reusing the same thing several times, in many different ways, allows you to pick up more and more from the content each time.
The simplest version of this would be to watch something several times, but many people find this too boring without the added interest of a new approach.