But why is this blank? One interpretation  is that they left it blank to show that God,   the Supreme power has no definite shape, size  or form. Many people think Hinduism is only   about Idol worship and polytheism, but even during  ancient times, Hinduism acknowledged and discussed   00:05:19 other philosophies like God is formless, this is  called Nirakara & Nirguna during ancient times.   Hinduism even discusses atheism, theosophy

Kotilingeshwara Temple