In Tibetan paintings Brahmarupa Mahakala, depicted as a central or secondary figure, has quite often been confused for an Indian teacher or mahasiddha, and actually, this has been done on purpose. The appearance of Brahmarupa as commonly found in Tibetan art is merely a place card holder for the Mahakala known as 'four faced' - Chaturmukha - associated with the Guhyasamaja Tantra.
In the Sakya Tradition of Tibetan Buddhism it was traditionally not permitted to show publicly the image of Chaturmukha to anyone that had not received the initiation into the secret practices and rituals. The form of Brahmarupa was used as an image that could appear on publicly accessible paintings without breaking any of the strict restrictions. This strict practice is still current within the Sakya Tradition today. However, the Gelug Tradition was not as strict and over the course of time many paintings depicting Chaturmukha were created.
Paintings of both the Brahmarupa and Chaturmukha depictions have now made their way into museum and private collections in Asia, Europe and North America. So, for the purposes of correctly identifying these subjects this topic has been discussed and the Brahmarupa Outline Page created.