The external dimensions of the Cube of Space, the Depths of Directions in the Sephirot 5-10, the Six Infinite Extremities, represent the manifestation of energy in its external or outer aspect. The inner creation is hidden in the four inner dimensions, or "Inner Court," where the initial stepping down of the cosmic energy from Ayn-Sof takes place via the thirty-two Nativot-Phaliot or "Wondrous Paths" and the inner space of Adam Kadmon is formed. The six directions have to do with Adam Kadmon's outer, or existential space, which is why the height, or apex of the cube, is twice sealed with Yod-Hay-Waw, and the other directions are permutations of those letters.
Each Sephirot of the Cube of Space is "sealed" with, or receives, the energy of YHWH in one of six combinations of the three root letters. This sealing can be understood from the inside, that is to say, in terms of the inner meanings, or semantic structure, of the "signs" (autiot) themselves, and the structures can literally speak for themselves.
This Cube of Space is the luminous Cube of Ayn Sof Aur , whose arms extend to infinity.
It is a map of cosmic energies and their functions in the manifestation of energy/structure and consciousness in the universe. The Cube of Space is an internal mapping of the familiar outer mapping of the wheel of the Zodiac and represents an inner view of energy in manifestation. Hidden within the Cube are the four inner dimensions. The seventh planet, found at the center of the Cube is Lavanah, the Moon formed by Tav, the last letter and Aleph's counterpart. What else could be at the center, but our own psyches?
The Seals represent the primary interplay of Yod: existence, Hay: life, and Waw: their interpenetration, in the "formation" or structuration of the universe. These categories are completely logical in their structure and relationship, as they provide the basis for existence itself, which was not a concern in the previous sepherotic categories. With the Seals, we begin with the simple permutations of three categories to yield six combinations and three axes as a framework for manifestation in space-time.
In verse I,13 of the Sepher Yetsira (Sefer Yetzirah), the Cube of Space is "sealed" with three autiot, Yod, Hay, and Waw   the three roots of YHWH. These three signs (autiot) signify the fundamental problems of existence (alive), life (in existence) and an active agent connecting, or engendering both life and existence. While there is no order to these coexisting signs, we may think of them in different orders according to different points of view.
Most commentary misses the significant double sealing of the 5th Sephira, formative of Shabatai.
Three axes: existence, life, and their interpenetration, or copulation. First, at the 5th (archetypal life) Sephira, existence alive joins with/is met by the response of the 6th (union/copulation) Sephira which in return adds the second, outer, life in response. Similarly with the other two axes, determined by life and interpenetration.
Later Kabbalah, including the Zohar and the Ari-Gra redactions, varied the order of the Seals. Suares follows the Short Version and other early versions in defining the axes respectively by single letters, Yod, Hay and Waw. The permutations of the final letters, differing, for instance, between the Short and Saadia versions, depend on the viewpoint within the Cube of Space: Adam Kadmon's or His image in the future.
When the Seals are considered in relationship to the Sephirot and their formative planetary energies, the logic of the three axes becomes apparent. The existential axis defines our place in the world, between our higher aspirations and material rights and responsibilities. The life axis runs from the future towards the past. The axis of interpenetration is our living sensual experience and our cognitive-perceptual response to it. All these axes pass though the center of our psyches and beings.
These seals are one layer of a complex, integrated, symbolic array: the Cube of Space. We must understand not only the significance of the axes and the ordering of the seals, but also their relationship to their Sephirot, formative autiot and planetary energy in contrary qualities, as an integrated (living) whole.