The guide is a bit lacking - I made such a foil based smart mirror and the mirror you get from just a foil is not good. I would more call it a reflective grey s

The guide is a bit lacking - I made such a foil based smart mirror and the mirror you get from just a foil is not good. I would more call it a reflective grey surface than a true mirror. So I would suggest getting a proper partially silvered glass sheet and getting the money for that by not using a currently overpriced and hard to get raspberry pi.