This is really interesting; thanks for compiling it!

I'm only peripherally in this fandom, but it's been a real experience seeing which things the fandom has decided are Something Khonshu Did rather than things that could happen in real life. My personal favorite is the person who offhandedly claimed nobody has a mindscape (headspace) in real life.

A thing I've been wondering about: When Steven's talking to Marc-in-the-mirror, does Marc take the body's perspective to see Steven in the mirror, or does he take the mirror's perspective and look out of the mirror to see IRL Steven?

Wait a sec, I just remembered a scene from the novel Anne of Green Gables. Let me see if I can find it.

Okay, here it is:

When I lived with Mrs. Thomas she had a bookcase in her sitting room with glass doors. There weren’t any books in it; Mrs. Thomas kept her best china and her preserves there—when she had any preserves to keep. One of the doors was broken. Mr. Thomas smashed it one night when he was slightly intoxicated. But the other was whole and I used to pretend that my reflection in it was another little girl who lived in it. I called her Katie Maurice, and we were very intimate. I used to talk to her by the hour, especially on Sunday, and tell her everything. Katie was the comfort and consolation of my life. We used to pretend that the bookcase was enchanted and that if I only knew the spell I could open the door and step right into the room where Katie Maurice lived, instead of into Mrs. Thomas’ shelves of preserves and china. And then Katie Maurice would have taken me by the hand and led me out into a wonderful place, all flowers and sunshine and fairies, and we would have lived there happy for ever after. When I went to live with Mrs. Hammond it just broke my heart to leave Katie Maurice. She felt it dreadfully, too, I know she did, for she was crying when she kissed me good-bye through the bookcase door. There was no bookcase at Mrs. Hammond’s. But just up the river a little way from the house there was a long green little valley, and the loveliest echo lived there. It echoed back every word you said, even if you didn’t talk a bit loud. So I imagined that it was a little girl called Violetta and we were great friends and I loved her almost as well as I loved Katie Maurice—not quite, but almost, you know. The night before I went to the asylum I said good-bye to Violetta, and oh, her good-bye came back to me in such sad, sad tones.

--L. M. Montgomery,
Anne of Green Gables

Huh.