It would be fair to note that the mirror would first have to exist for the first 2000000 years and then in another 2000000 years people would be able to see what happened after the first 2000000 years. By then humans won't be here for sure.
A "small" mistake in the picture though. The distance possibly shown there is not really a million light years away. If it was, earth would need to be a lot smaller, in fact unnoticeable!