This design based on 21/3 or 3 x 7. As 3 it expresses the new creation coming forth from the joining of 2 unique forces. It is supported and based on the initiating power of 1 and the understanding of duality of 2.
As it was created as a multiple of 7 it also carries the energies of intellectual and spiritual development, philosophy, metaphysics; the mind in search of its reason for being.
Open your heart and receive the gifts of the spirit - it is the gift of your Self.