This is what is called as Aniconism in Islam and is the prohibition of the depiction of people and/or animals in art. Actually, this is also applied to mental representations. This has long been before since then. The main reason as to why Islam prohibited the depiction of people and/or animals in their art is just a means to combat and suppress idolatry. Islam merely condemns idolatry. With this, Islam art was dominated by geometric figures and shapes. But then, figurative ones are also present privately on homes and the palace.