That question only occurred to me today. The Israelites were surrounded by cultures which made many images. If you look at the other cultures of the Eastern Mediterranean in the first millenium BC and earlier, the 2nd Commandment looks very unusual indeed.
Could it have anything to do with the Hebrew alphabet, and the contrast between it and hieroglyphs? Just as we don't know for sure when the 10 commandments originated, and whether they originated in oral or written form, and to what extent they may have been modified before taking the form with which we are familiar, we also have no definite idea at all about how old the Hebrew alphabet is, and what exactly the relationship was between various alphabets, Hebrew, Phoenician, Greek, and others, while they were forming. It's clear that those 3 alphabets and others, including the one we're using now, are closely related. It's clear to us now. But that doesn't necessarily mean that it was clear to the Hebrews when the 2nd Commandment was being formed -- whenever that was: 1000 BC, or earlier, or 600 BC, or later. One thing we do know is that hieroglyphs and cuneiform and alphabets were used side by side in the ancient middle East for a very long time. It seems entirely conceivable to me that, to the Hebrews, when they were making their 10 Commandments, their alphabet was the only one they had ever heard of. Perhaps they associated that alphabet with what was domestic, familiar, comforting and good, and hieroglyphs with everything which was foreign, unknown, foreboding, frightening and evil.
Could it be that the ban on graven images began as a rejection of hieroglyphs? Further, is it possible that the Israelite God with His omnipotent power and unpronouncable name and unfathomable ways came from the abstract nature of the Hebrew script, which contrasted with the much more concrete and comprehensible nature not only of the pictures of the pictures of of the deities of the polytheists all around, but also with the pictoral nature of their writing?
Or was it the other way around, did an awesome and unapproachable Supreme Being, whose appearance and name were unknown, give rise to the abstract system of alphabetic writing? Chicken or the egg?