“The Inpaint feature expands artists paint workflow options and using it for things like cleanup is really quick and intuitive thanks to the node being GPU accelerated and the ease of using paint strokes or roto shapes to drive the alpha being used to determine Inpaint regions,” noted the Nuke team.
You can use the Stretch knobs to control the direction of the Inpaint for finer adjustments. You can also adjust the level of detail that is pulled through the alpha, and pull this detail from another part of the source image or even from a second image. This can help integrate Inpaint patches, or even cloning new textures into the image.
You can learn more about the tool here.