Answer: Reality differs from illusion as it is perceived by our senses to the degree that we become similar to the upper force.
Let’s imagine the ego as a vessel in which we perceive different effects. If we correct a small part of our ego with regard to the upper impact, we will feel the upper world in that space. We will feel our world in the whole uncorrected part.
It turns out that a Kabbalist sees two worlds simultaneously. In his uncorrected desires, he sees the corporeal world, and in his corrected desires, he sees the upper world, and that’s the way it is until he fully corrects himself. In both cases, he always feels everything inside his desire.
In order to feel the upper world, we must first restrict our desire (Tzimtzum Aleph), then build a Masach (screen), the Returning Light (Ohr Hozer), and only then can we begin to receive.
Only then will we begin to feel the upper world within us because now an equivalence of attributes is formed between us and the upper world.
From the Kabbalah Lesson in Russian 11/27/16