The Second Commandment

The first clause, prohibiting visual representations of heavenly things, guards against degrading the heavenly to the level of the common. "Thou shalt not make unto thee any graven image, or any likeness of any thing that is in heaven above."
The second clause, prohibiting the worship of earthly things, guards against exalting the common to the level of the sacred. "Or that is in the earth beneath, or that is in the water under the earth: Thou shalt not bow down thyself to them, nor serve them."
Thus the commandment can be violated in two ways:
1. By making visual representations of heavenly things.
2. By worshipping earthly things.
One degrades the heavenly; the other over-exalts the earthly.

The worship of graven images violates both clauses. In bowing to common wood or metal or stone, the second clause is violated. And if the image is to represent God, its very existence is a violation of the first clause.