Supercropping???

I know what it is and have read many things about it but havent found a real detailed description of the process,so if someone may be kind enough to shed a bit of light on the subject i would really appreciate it.

umm... sig

http://www.youtube.com/watch?v=H1YEc7ENd5E

min 2:00

thanks a visual reference was all i really needed,cant believe i didnt look on youtube sooner