You're right about the Christian imagery; most of that is 180 or later. But the Jewish imagery is earlier, if I recall. Of course, the issue is different when God is incarnate and the God-man is being depicted, but the depiction of angels does not seem to have been an issue for Jews (even prescribed in the Torah!).
I actually really have to disagree here. On a semantic level, "likeness" is probably something like "form" (the Hebrew is temunah, and related to min, kind) in the same sense that idols are in the form of the god they represent and receive the worship on behalf of the god. On a literary level it is probably just standard Hebrew parallelism, repeating the same idea in other words.
The God's Word translation, which is a contemporary English translation meant to be readable but without being a paraphrase (and usually does an excellent job conveying the sense of any given passage), renders it thus: "Never make your own carved idols or statues that represent any creature in the sky, on the earth, or in the water. Never worship them or serve them, because I, the Lord your God, am a God who does not tolerate rivals."
And I think it is worth noting that, while Jewish tradition is aniconic when it comes to portrayals of divinity, Exodus 20 is pretty specifically speaking about depictions of creatures (including other gods) receiving worship, not depictions of God himself. It is an elaboration of the commandment to worship God alone, not a separate commandment in-and-of-itself. I'd contend that the theology behind the prohibition of imagery in worship centers around the twin reality that images receiving worship are not gods and that prior to the incarnation God has no image that can be depicted. Therefore there is nothing, prior to the incarnation, that can properly depict anything that might receive worship through imagery. But that situation can change afterward.
Essentially, I contrast the (official) theology of icons in Eastern Orthodoxy with the theology of statuary in the Ancient Near East.
Ancient Near Eastern and even Greco-Roman statuary fills in for the presence of the deity. The idols are dressed and undressed daily, bathed in perfume and oils, and, especially, actually receive the devotion and worship in place of the deity. The statue receives the worship directly, and therefore the deity is worshiped.
In Orthodox iconography, the icon itself isn't an object of worship because fundamentally it isn't an object. It is a window, and that window allows us to see into the heavenly realms or into the sacred past or into the eschatological future, and that window allows us to worship the person pictured therein (God the Son) directly. In fact, it does exactly what we do mentally do anyway: we imagine/image Christ while we worship. But an icon does that same thing in an objective, public, and communal way rather than in a private and subjective way.
Two caveats to this, though.
First, statuary isn't really a probably in-and-of-itself (obviously, since God commanded angelic statuary on the ark), but only when it is a recipient of worship or a vehicle for worship. At best, it can be a psychological aid and reminder prior (either conceptually or chronologically) to worship. In that sense a crucifix (or other statuary) may be an inducement to meditation prior to worship, but it cannot be an object of meditation or worship (as in paganism) or even a vehicle for meditation or worship (as with icons).
Second, the Eastern Orthodox have gone entirely overboard with icons, and have begun treating them as direct objects of substitutionary worship rather than as windows into heaven. Icons are washed, robed, spritzed with perfume and incense, etc., in exactly the same way pagan statues were. That is equally unacceptable.
All this goes back to the fact that I think the prohibition against three-dimensional images is primarily (1) merely a subset of the prohibition against the worship of other gods and (2) simply a consequence of the fact that prior to the incarnation God had no visible form. In fact, my reticence against statuary has less to do with Old Testament commandments than it has to do with the the fact that it somewhat falls outside the theological justification for the use of two-dimensional imagery in worship.