I've heard the Trinity explanation, and it does fit the Christian perspective. But keep in mind that Jews follow the Old Testament (for a looong time), and they believe G-d is indivisible. Their explanations I found say it's either the "royal we", or he was addressing his angels.
That second explanation suggests that angels naturally look like humans, though, which is a little odd. Some angels can at least appear human-like (enough that the people of Sodom called them men). But other angels are 6-winged beasts (Seraphim) or burning wheels (Orphanim).
Trying to figure out if even Satan's default image is humanlike, but apparently not. He was/is a cherub. Which are *not* exactly cute winged babies. They are large enough for God to ride on, and have four faces - Human, Eagle, Lion, and either Ox or "cherub" (indescribably unique, I guess).
It's possible that the angels (or all the ones God was addressing then) have a human-like form, and that shared image is what God was referring to.
That would also explain why God's appearance is supposed to be beyond comprehension, and nobody can see him without dying, and yet many people had face-to-face meetings with him. Jacob even *wrestled* with God, and WON. And was awarded the
existence of Israel:
http://skepticsannotatedbible.com/gen/32.htmlAwesome origin story aside, it suggests God (like the angels) has a limited human body he can walk around in. And while this obviously isn't the true image of heavenly beings, the fact they have it in common makes it a fine image to create humanity in.
The bible is *fascinating* sometimes.