Secondly there are all the goddesses that are like Diana, who we may call a Mirror of Diana. Diana at Nemi is called Diana Nemorensis. Sometimes she is called the Scythian Diana, and is related to Artemis, Cybele and other goddesses like Hecate, Nemetona, Trivia, Isis, The Black Madonna or Luna. All of these are mirrors of Diana.
Thirdly it is a method: To see all the images of Diana we have to use a tool. Diana's Mirror is our magic tool through which we can her mirror-images. But the mirror's magic can be used by others as well. If Jesus looks into it, he'll see Dionysos, perhaps Tammuz, or who knows?
So this is what we are going to do: to look into Diana's Mirror from different angles and see what turnes up!
By the way, there also is a novel by AR Homer (!) called "The Mirror of Diana", which you can read online.