Pete Enns illustration is certainly very valuable but may be completed with what I think is the main principle of “exegesis”: “Scripture interprets Scripture”.
Accordingly, to better approaching the mystery of the “image of God” it seems fitting to keep in mind passages like the following ones:
Colossians 1:15
The Son is the image of the invisible God, the firstborn over all creation.
Hebbrews 1:3
The Son is the radiance of God’s glory and the exact representation of his being, sustaining all things by his powerful word. After he had provided purification for sins, he sat down at the right hand of the Majesty in heaven.
Ephesians 1:4
For God chose us in Jesus Christ before the creation of the world to be holy and blameless in his sight.
Acts 17:28
As some of your own poets have said, ‘We are his offspring.’
1 John 3:2
we know that when Christ appears, we shall be like him, for we shall see him as he is.
John 6:57:
The one who eats Me will live because of Me.
John 14:23:
Jesus replied, “Anyone who loves me will obey my teaching. My Father will love them, and we will come to them and make our home with them.”
All these passages support the idea that, according to Scripture, humans are in the image of God because God became true human in Jesus Christ, and then we humans are image of Jesus Christ, i.e. of God.
And this is very much what Pete Enns says after all:
The images a king set up to represent him are representations of the king’s body; God’s body is the body of Jesus Christ, the image of the invisible God!
In this respect I have many thoughts!
To avoid going lengthy, could you please specify in which particular aspect or context are you interested in?