The projected image is not typically indistinguishable from normal vision, namely in that there will be an "ephemerality" to the image. Some examples of this ephemerality:

- the projected image usually has a translucency, i.e. it doesn't also block what is behind where it would be physically if it were really there

- the projected image requires sustained concentration and mental effort to maintain detail, and if you let any aspect of your mind wander or stray from the task, the translucency increases, it may pop out of the visual field, or lose details

- the projected image (say, an apple) doesn't have full details at every particular point, i.e. if I focus on where the stem would be, that detail intensifies, but the surrounding areas become more ephemeral; with a real apple, this happens somewhat depending on the focal point too, but not nearly as much

- the projected image can be made less ephemeral and more rich and stable with the use of pscychedelics (e.g. psilocybin) or quasi-psychedelics (e.g. cannabis)

So, yes, you can "see" it in reality, but not, in most cases, to the degree that you "see" a real apple. Often the ephemerality really does manifest in a way extremely similar to how an afterimage persists, but this isn't always the case.

I created https://news.ycombinator.com/item?id=49469365 to see how many people perceive things this way.

It is quite possible that this is drawing a line, as you say, between hyperphantashia and regular phantasia, though I'm not yet willing to give up on the idea that we are just giving subjective names to the same phenomenon.

To wit, when I "hear" things with my "mind's ear" I can "hear" them very well in all the layers and components, I can "hear" drums and guitar and bass and voice, etc., but they are very clearly in my head -- they do not have a location in real space the way that real sounds do; I can't "hear" a sound so loud that it makes me cringe or so quiet that I have to strain to hear it.