RE: Mirror ground blind??
I think the key to it would be to simply make the sides angle downward X number of degrees so that it was only reflecting ground level surroundings out to a certain yardage. This would also eliminate sun glare and animal attacks unless an animal was right next to it looking upward.
The blind itself should be shaped like a Chinese take out box.......bigger on top sloping inward to the bottom.
Pretty simple concept and wicked if you really think about it.
The next trick would be making it portable, and practical. If you think about it you could do the same thing pretty easily with a full length mirror with a porthole cut in the glass to see.......I bet if you angled it down and simply walked slowly and quietly you could get scary close to a lot of animals. Put some handles on the backside to carry it and it might be the ultimate antelope spot and stalk blind. What's the animal going to see? Just more of everything around it.