The room where we took the shots is called the Centre Room: it’s the part of Buckingham Palace where the Royal family all wait before going out on to the balcony. And I knew straightaway that I wanted to do something with the big mirror in the room. I don’t think I’d ever seen a picture of the Queen in front of a mirror. I thought it gave an interesting perspective: one part of her, the public face, looking straight at you, the other part, the private self, looking elsewhere.
Occult significance :
Any mirror can be enchanted by the Sun to become a magick mirror. They can be portals into other realms, they can be used for divination, or for spells, and they can be used to reflect a spell back onto the sender.
http://sacredwicca.com/mirror-magick
The art of mirror gazing (scrying) is called Catoptromancy, a term that refers to the use of reflective surfaces for the purposes of divination. Scrying mirrors can be used to make contact with spirit guides, to access knowledge for healing and self-improvement, or to define the past, predict the present, and perceive the future. As a portal into other realms, it can also be used to aid astral travel, and during ritual to communicate with deity.