I do not know.

I mean, I can guess, theories, hints, but the dream moon just blindsided me that I am probably wrong.

But my guess is that Jade’s dreams are prophetic in some way. She gets her powers from it, or uses her powers to visit, or whatever. Who knows, but since she visits this place so often that it is second nature to her, she was probably trained with this ability.

Now, while in Moon City, we saw the White Knight citizen/person. Dressed different, but still the same. So, either this is her actually transporting to the real life moon palace, or she is condensing all the future information into one single place.

But that doesn’t fucking explain John! It can’t be a physical place otherwise wouldn’t their bodies or dream-selves be in danger? And if it was a condension of Jade’s future knowledge, then how would John’s poster drawings be seen in real life.

God the Moon is a mess.

Best guess, the Golden Moon is the fucking subconscious dimensions where everyone’s dream selves/subconscious goes to. It happens to be the golden moon because Jade is a fucking dream warrior and let’s her future vision populate it, and her connection to her friend’s subconsciousness because of her possessing abilities.