2 way mirror

I've managed to blag a free bit of 2 way mirror/glass for the next step of my practice. I'm interested in moving the '4 minute' women forward by placing them in front of a mirror rather than the camera len's to see how they change, it will obviously form a different relationship between the subject and the viewer, does subject also become viewer (of self)? does she become more animated or more comfortable with the familiarity of self looking back at her? does it then create a 3 way relationship between subject, subjects reflection and viewer behind the mirror, the lens? Ive had to do research on how to actually light it, it needs darkness behind the camera, well light in front, lighting the actual subject as bright as poss. am going to experiment with black fabric over camera to see if that works before i start building myself a black box!!