There is a type of optical illusion in which one sees a black image against a white background, but with a change of perspective, the picture reverses to show a white image on a black background.
The eye is guided to pass from one perspective to the other by certain flaws, such as lines that do not meet or unequal proportions, and these allow the eye to switch from one point of view to the other.
Our world is so precisely balanced that we can perceive it equally with or without an awareness of the divine presence.
A person who looks only at the natural world can live a full life without ever discovering the existence of another dimension.
And it is possible (although very difficult, requiring rigorous training of one's consciousness) to always see that other dimension as well, so that one's gaze changes focus and suddenly the proportions are completely reversed.
Elements that had been considered essential are now seen as only decorative, and what was considered reality is seen as no more than a background to reality.
–Rabbi Adin Steinsaltz
From Understanding the Tanya, Chapter 33, by Rabbi Adin Steinsaltz