Everytime I get this off my chest, the board lights up. So, I'll paraphrase this.
God said let US make man in OUR image. This denotes that God didnt make man and woman by itself alone. When in the next few verses God said that I alone made man and woman. While saying this, God said I am a jealous God and nothing is before me. This also denotes that Something is before God. For if nothing were before God, there would be no reason to be Jealous.