As I understand it:
Man is created in the image of God, not the other way around. Human beings do not describe God anthropomorphically; rather, human beings are described Theomorphically, in terms of how they reflect God.
When St. Irenaeus speaks of God having two hands, human hands are revealed to reflect something of God. When God is said to have a face, we learn that faces somehow reflect the way God is, etc.
God's Otherness, of course, is something beyond this method of description. But in terms of God's ecstatic relation to, and communion with, the world, this way of speaking seems right and just. And we learn of God's Otherness by acknowledging the absolute otherness within/about every human person, too.
When people say that we describe God "anthropomorphically," they are probably just being imprecise. They could also mean that God is being described in terms of how fallen humans are; I personally don't believe that the Old Testament describes God in terms of how fallen humans are. That would be Marcionism, and (to use harsh language) a rather cowardly way to address the Old Testament.