Several Bhagavathy temples in Kerala (temples dedicated to Devi or Mother Goddess Shakti) have Kannadi Bimbam (mirror idol or murti made using mirror). So why is Bhagavathi worshipped in the form of a metal mirror?
Bhagavathi worshipped in the most Kerala temples are in ferocious form. She has just killed Darika or some other demon and people are unable to control her temper. In some temples, She is getting ready to face the demon. It is believed that there is too much shakti in Mother Goddess and if she is worshipped in her human form, a mere gaze of her upon devotees would destroy them. To contain the ferociousness of Mother Goddess Durga she is worshipped in Kannadi Bimbam.
A Kannadi Bimbam is an exquisitely caste metal mirror, which resembles a human form with its leg-like handle and rounded head.
Kannadi Bimbams are cast in bronze or Panchaloha, a five-metal alloy of copper, silver, gold, tin and zinc, in the lost wax method by Musaris or traditional metal casters. The mirror idols are made of granite, wood, or stucco.
Symbolically the Kannadi Bimbam extols the teachings o the Vedas and Upanishads – Aham Brahmasmi – I am Brahman or the Supreme Truth. The worshipped and the worshipper are form of the same Supreme Truth.
Kannadi Bimbams are worshipped mainly in temples in North Kerala.