Two comments . . .
1. I read, a long time ago, that mirror blinds were illegal for hunting game. These were used by goose hunters at one time and were considered too concealing and legislation was written to prevent their use. If the legislation is still on the books this could be problem for these blinds.
2. I was watching a show on Special Forces equipment and they used mylar reflective sheet about 3' wide and 2' high that rolled up like a scroll. It was held open with a plastic stay. They had to approach a farm house surrounded by mown fields and no cover. From the farmhouse it all appeared normal but there were actually a dozen Special Forces 25 yards from the house. They simple put the mirrored mylar in front of them and crawled right up to the house.
3. I can see a big buck in rut see his reflection and "bam" - you've got a great story to tell.