In my experience, it can be tricky to tell dreams from astral projection. And dreams from waking life for that matter. At least once I've seen Earth in a similar way to you - the only difference being the angle - and it was very much astral projection rather than a dream. The biggest difference I've found between the two states is that in the case of projection, I can remember the process from the time I began relaxing, through the beginnings of the astral sensation to the end of the session. As opposed to dreams, which have a gap between the memory of relaxing and the image. The dream just seems to suddenly begin, like starting a movie halfway through.
"Sometimes you will act as an angel to someone else, perhaps without even knowing it. One day someone comes up to you and says, "You saved my life." You look at her astonished, trying to remember when you even saw the person before, the meeting meant so little to you at the time. "Don't you remember? I was standing on the bridge, staring at the water, and you passed and said, 'Good morning'."