Thanks everyone for your thoughts. I think the multiple-reality thoughts are on topic, because multiple realities must have something to do with how 'astral' stuff works.

I'll start off by continuing about mirrors, then come back to the multiple reality topic. I have a better handle on mirrors, even if its a fairly trivial point....

Objects don't actually appear reversed in a mirror. If you write on a piece of transparent plastic, and hold it up in front of a mirror, it looks exactly the same in the mirror as it does directly. Or use scissors to cut a word or a letter out of paper, and hold that up, and it looks the same in the mirror.

If you hold an open book up to a mirror, and the text looks reversed, its not reversed because of the mirror, its reversed because you turned it around to face the mirror. And the reason its not upside down is because you didn't turn it upside down. If you turn it to face the mirror by turning it upside down instead of left-to-right, then its upside down and is not reversed left-to-right. Likewise with images of people, though most people turn left-to-right or right-to-left to face a mirror, rather than hanging upside down from the ceiling.

If you could see your own face without a mirror, while facing in the direction you are facing, it would look like it does in the mirror. It looks reversed to other people though, without a mirror, because they are facing in the opposite direction as you.

I think that if 'you' did not have a particular location in time and space, and therefore no vantage point, and did not 'see' things by focusing light through a lens, but could still somehow see, then you could see things like how they appear in mirrors. I think that there are astral entities or higher selves or gods or something like that which perceive things this way.

I've previously mentioned that I had a dream once where I could see an object from several directions at once. I was still seeing the surface of the object, but my vantage point was somehow not a point, it was the whole surrounding area. And my vision wasn't just multiple views cobbled together or warped, the 'scene' was three dimensional. This contrasts to my usual field of vision, which is three dimensions projected onto a two dimensional surface which I sort of pretend is three dimensional. I think if you look around you, you can see that you only see two dimensions. You imagine depth, but in terms of the visual information present, objects are like a lot of cardboard cutouts. Yes you get a little bit of stereo information from having two eyes, and from inferring distance from context and shadows, but its still an enhanced two-dimensional view, not truly three dimensional. My dream, in contrast, was two dimensional in that I was not seeing into solid objects, but the objects were embedded in a three dimensional visual scene. I have no idea how something like that would work, but that is what I experienced, so it is possible, apparently.

Suppose that the 'astral plane' were a mirror, and we could use it to see reflections of physical objects. The objects would not be reversed, for the same reason objects in a physical mirror are not reversed. I think this gets closer to the point that was in the dream I started the thread with. I have to stop now because my plane is boarding, but I'll continue later. Yeah I realize I haven't said anything very profound or significant so far, but its all I've got, and I have to start somewhere. The 'other worlds' come in because most or even all of the objects we see reflected are somehow in other worlds, apparently, though I'll share more of my thoughts on that later.