Viorocana Buddha seems to have special meaning and post in Buddhism. Virocana looks like to have a similar meaning with the concept of GOD in Aristotle's philosophy, in my guess. Buddhism is not my major interest, so my knowledge is limited to explain the meaning of Virocana. But in many point, for example, the characteristics between Aristotle's concept of God and Virocana looked like very similar. Aristotle described God as the principle working the Universe. In my view, Virocana also has the same characteristics as Aristotles' God.
The Hall for Virocana in this temple was named 'Jeok Myeol Jeon' which meant 'absolute silence place. Here they describe Virocana as of the silence. The silence means the principle of the Universe being moved.
Virocana Buddha Statue is a symbol of its existence. We can't not see his appearance. We just could feel him elsewhere. Only enlighted people can feel its existence.
There were other Buddha statue and the painting. It was a pity that I could not understand the meaning. But I knew those were great things.