Beginning with the breaking of the worlds and the mixing of Bina and Malchut, Partzuf SAG serves as a stamp, a matrix, that imprints its form of Bina connected with Malchut in all the material on all the levels: Atzilut, Beria, Yetzira, Assiya, and our world.
The root of all worlds is above in the head of the world of Atzilut, because SAG itself pertains to the first restriction (Tzimtzum Aleph), and its influence does not reach the worlds of the second restriction (Tzimtzum Bet) directly, but only through the Se’arot (narrow hair channels).
These threads descend like projections all the way to our world from the head of the world of Atzilut, repeating the same structure over and over, put on the same axis, like a skewer. This is why all the Lights spread like parallel rays from above downward.
However, this only pertains to the structure of the worlds and not their behavior! The rules of behavior in every world correspond to its degree, and, for this reason, they differ. The world of Atzilut is all for the sake of bestowal, and lower worlds—Beria, Yetzira, Assiya, and our world—all operate according to their level.
From the 3rd part of the Daily Kabbalah Lesson 12/1/10, Writings of Baal HaSulam