A human being has many levels, what a person sees as the self depends on what level they are looking at at that time, or their consciousness is on. The nature of that self, is a give away as to what level the person is on:
The ego: I, me, exclusion or separation from others. Thoughts about how great they alone are. Subject to external circumstances.
The self of a person: who they really are, has a sense of who they really are, true to themselves. The higher nature of that person seen impartially with the universe. Has an inner world and not just buffetted around by external circumstances. At the level of their soul and in touch with heaven.
The divine level: All is one, the person is an infinitely tiny part of that one and joined with that one. There is no I, me or mine, total submission to God.
At the beginning a person is like a thin torch beam, they can only be aware of one level at a time. As their consciousness improves, their beam becomes wider and wider, so they can be aware of more and more levels at the same time.
The aim is to wake up to higher centres, so they can be aware of the higher levels of the psyche, spirit, divine and god.
Only the higher centres can be aware of the higher centres as they are on the same frequency.
How to do this
The higher centres can communicate through to the ego through images, sounds, smells, touch and so on in the mind. This is the subconscious and other levels communicating with us.
The mind is far less dense than the physical level, hence it is easier for these levels to communicate with us through the mind.
The ego is a mirror that can be pointed anywhere and through the images we see the things. A lower level example is how the body communicates with the mind to tell us that we are hungry.
Using images we can imagine anywhere and see it to our mind. However once we have gone somewhere, it is equally important to make sure we come back to ourselves by looking at ourselves and our body.
It is a bit like a television set, we cannot perceive a television signal directly, so use a television to see what is being broadcast. The subconscious and upper worlds communicate with the conscious mind using words and pictures.
So we can create symbols in our minds to represent things and use them to send and receive messages with the upper worlds and our subconscious.