Fotodiox Vizelex RhinoCam for NEX first results

I'm afraid that I don't understand the advantages with the rhinocam?

You attach your camera to a mediumformat lens and then take a series of shots that you stitch together to compose a photo of higher resolution?

Why not attach an ordinary telelens and take the shots with that and then do some stitching to achieve higher resolution?
What am I missing here? Why is it better to use the Rhinocam?