A more sophisticated answer, which emulates the principle of indeterminacy in physics goes something like this: The image is a not an object, nor a symbol, nor an aspect of dream "content," but rather a mutable interface between the dream ego and the unseen, intrusive content that is surfacing in the dream. The source of the content can be "local" or "nonlocal," or a combination of both. That is, the dreamer may be accessing a memory, or may be receiving information/essence beyond the boundaries of the self. In the act of perception, the dream observer sees clearly, or perceives through filters that distort the incoming content, thus co-creating an image that changes constantly as the perceiver's response to it shifts in real time. So that's where I arrive at the term "mutable interface" to describe what the dreamer actually sees. The image is a moment-to-moment vectoring of the dreamer-dream content interaction.
So the question, "Is it really you?" necessitates a deconstruction of the image into "projected" and "received" components. If the dreamer can say that he or she is open to the dream character, and has no distorting feelings that can be projected upon the person, then the essence of the person may be free to express itself through the mediating image. But this is rarely true. We almost always have impressions, biases, fears, needs, etc., that are projected onto the significant others in our lives. So the resulting image is likely to be a "cocreated" product that has to be analyzed as such.
I dreamt of my deceased mother in a lucid dream two nights ago. She appeared younger than she was when she died, and her face was lit up in a golden light. At first I felt that she was soulfully present, but then her face began to look less familiar, and so I concluded in the dream that her essence was fading away, leaving behind an inaccurate rendition of my mother's actual self.
But then again, who can ever know the answer to this question? Van Eeeden, the first lucid dream theorist ("A Study of Dreams,"1913--you can find it on the web), believed that a "felt sense" is the only way to know if a dream character's soul is manifesting through the dream imagery. But this criterion is highly subjective, and not likely to satisfy a more empirically minded researcher. Henry Fielding's words from his book Tom Jones come to mind: "Until they produce the authority by which they are constituted judges, I shall not plead their jurisdiction." In the domain of the soul, empiricists can never really compete, because there is no foundation upon which they can base their conclusions.
So is it really you? Only I can say.
