Imagine a glass window when writings are reversed if you look from other side though that's still different from mirror, and mirror is actually the second reflection since first one is what our eyes sees.
I love the idea of 2 mirrors reflecting each other for eternity, that I think time and our lives are like that each image in rear mirror could be considered our past moments and front mirror is our future but with time every reflection is a different image but all are there at the same time, so in other word you can go back for eternity in time and still exist as well in the future.
This idea is truly mind blowing :)
So mirrors are like pages of a book if you hold a page in light you can see the content from both sides and just turning the page from left to right which does the same as back to front.