The couples of Buddhist iconography celebrate this deep harmony of the sexes. The purpose of this dynamic was the creation of partnerships devoted to the realization of the ultimate truth.
The father-mother union image is not an example of erotic art, but is a manifestation of the Buddha's highest spiritual essence. More than metaphorical, to the devout this image is concrete evidence of the existence of great spiritual attainment. The female (mother) represents transcendent wisdom: the direct awareness of reality as the Buddha experienced it and taught it. The male (father), represents compassion for all beings, which is the natural expression of such wisdom. Their union, although exquisitely blissful, is ultimately undertaken out of compassion for the world. This sacred communion of the male and female elements generates waves of bliss and harmony that turn the world into a Mandala (container of essence) and showers forth a rain of nectar that satisfies the spiritual hunger in the hearts of living beings everywhere. Modern depth psychology has recognized such images to represent the deepest archetypes of the unconscious, integrating the powerful instinctual energies of life into a consciously sublimated and exalted state.
This description by Nitin Kumar, Executive Editor, Exotic India.