This image of Vairochana derives from a Japanese model and represents the major Buddhist deity revered in Shingon Buddhism.  Also known as Esoteric Buddhism, Shingon uses a complex mandala for contemplation and ritual with Dainichi Nyorai (Mahavairochana) as the central deity. 

In 806 AD Kukai returned to Japan from China and founded Shingon or “The True Word” which was inspired by Mahayanist Tantrism then popular in China where it was known as Chenyen.  This doctrine identified the universe with the supreme Buddha, the great solar Buddha, Dainichi Nyorai or Rushana-Butsu (Vairochana).  All the divinities, Buddhist or otherwise, were considered emanations of this Buddha and were no longer considered only protectors of Buddhism.

The primary mandala is the Mandala of the Two Realms made up of the Diamond Realm and the Womb Realm mandala. Here Vairochana’s hands are held in the “knowledge fist” of the Diamond Realm, with the raised index finger of the left hand clasped by the five fingers of the right hand.  The five fingers of the right hand symbolize the five elements penetrated by the Buddhist essence represented by the index finger of the left hand. The gesture also symbolizes the mystic union of the material with the spiritual of yoga practice, which in Tibet and Nepal takes the form of the ecstatic Yab-Yum embrace, but in China and Japan is sublimated in this mudra.