Steve, admit it, the "Sky mirror" is utter nonsense, that you made up in the absence of anything remotely plausible.
There is absolutely no proof, no shred of evidence, not even anything that remotely suggests this mirror actually exists, and you have no idea how it would even work.
I thought the sun was a "spotlamp" shining down? Therefore the mirror is at a lower altitude than the sun? Explain then how it distributes the light, and why we cannot see it please.
Otherwise, keep that sort of nonsense away from the upper, serious discussion fora.