If the Commandments were in order of importance, this would be the second most immoral thing you could do.
Deuteronomy, Chapter 4 - once again Yahweh brings up the Second Commandment. "When thou ... make a graven image, or the likeness of any thing, and do evil in the sight of the Lord, you shall perish upon the land and be utterly destroyed."
I'm trying to understand this irrational paranoia about the graven image. While I'm convinced the punishment is ridiculous, I kind of understand what the authors were trying to get at. A graven image isn't the thing itself, or the 'ding an sich'. It's merely a representation of something.
So, a drawing of a bird, for example, is nothing more than a manmade representation of a bird. It's obviously not the real thing. Apparently, to the ancient Hebrews, this was a problem.
Since they were the descendents of Sumerians and Canaanites, it's quite likely that a lot of Israelites still held on to the beliefs in other gods within the Sumerian/Canaanite pantheon. And they probably had a lot of idols to represent each of these gods. The Israelite priesthood, who was really trying to get this Yahweh thing off the ground, decided that the best way to deal with this was to ban graven images entirely.
The Catholic Church, a 1000 years later, approached the subject with a different strategy. Instead of banning idols, they simply incorporated their own images to substitute the idols of various barbarian tribes. The Catholic saints are usually the replacement of various pagan gods. For example, St. Nicholas replaces the Greek god Poseidon.
I'm inclined to believe that the Catholic Church's tactic was a little more successful. It incorporated more people, and it didn't alienate them at all.