Guessing that it photographs an image on a ground glass screen inside there. That kind of adapter became popular with some people 10-15 years go as a way to get shallow depth of field with small chip camcorders. The good ones were expensive, the others had issues with vignetting and of course you lost a few f-stops from the ground glass.
Might be fun to play with, but a bit like "whipped cream on a t**d". The iPhone is great for all-around use, shot a bunch of fun clips at my Granddaughter's birthday party last month. But for more serious work, think I'll stick with my Sony XDCAM-EX CineAlta until I can afford an upgrade to another real camera.
Soderbergh likes to use cheap video cameras for feature films. Went to see one that he shot on an Canon XL-1 somewhere around 2002 (?) thinking it would be cool on the big screen. It looked really terrible though!
I'm fairly certain it is straight thru the lens. Probably lose all the functionality in the lens a person pays big buck for. The only successful cross mounts I have seen are those that allow Canon body owners to utilize Nikon lenses.
