Of course you can't portray God, nobody knows what he looks like! But we all have images to worship or remind us that we are mortals. Religions are the primary and most important source of all art, wherever you are, what ever your background or culture is.

Sometimes we can cry when we look at a photo.
We don't get emotional because we look at a piece of paper, but because what the picture represents. Because of that we may put a nice frame on it, place it somewhere important. We may even put a flower next to it, or a candle.

We may even go so far as to worship it, that is the idea it represent, not the thing itself, In Hinduism it is called 'darshana', Hindus look beyond the thing itself, In Christianity this may be a little different: "This is the blood of Christ"

In Ghana I got this effigy from a young streetseller. He had it standing against a tree and it had obviously a special meaning to him (as it has for me know). He was only willing to part with it because I also bought a beautiful handcarved mask. Earning some money was more important for him.