Because we don’t limit God. According to Islam, God is unlimited. So we can’t picturise. God cannot be represented in any shape. Also, there is no mental image of God in the mind of Muslims as God is beyond perception. “There is nothing like unto Him” (Quran 42:11)
Why there is no Prophet Picture?
According to the teachings of Islam, nothing and no one deserves to be worshipped except the Creator. Placing a painting or a statue of Prophet Muhammed or other prophets in the mosque can attract people’s attention. Some people may bow to the Prophet out of respect or even pray to him. This is very wrong because Prophet Muhammed is not God or divine. He is a human being who used to eat and sleep. God, on the other hand, does not need food to survive or sleep to get some rest. Unlike God, humans are limited, needy and dependent beings. One cannot be both man and God. According to the Qur’an, associating partners with God is a terrible sin that will never be forgiven unless we repent before we die.