The number of ways we can misunderstand what that means is vast. And, frankly, I think the number of ways we can rightly understand it is not singular: God teaches us different things at different times and He often uses the same scriptures to teach different lessons - it's fascinating!
Then God said, “Let Us make man in Our image, according to Our likeness; and let them rule over the fish of the sea and over the birds of the sky and over the cattle and over all the earth, and over every creeping thing that creeps on the earth.” God created man in His own image, in the image of God He created him; male and female He created them. God blessed them; and God said to them, “Be fruitful and multiply, and fill the earth, and subdue it; and rule over the fish of the sea and over the birds of the sky and over every living thing that moves on the earth.” (Genesis 1:26-28)Dorothy L. Sayers, brilliant woman, friend of the Inklings, creator of Lord Peter Wimsey, and wonderful lay theologian, observed that when God said, "Let Us make man in Our image, according to Our likeness," the only thing we know about God is that He is creative, He has the desire and the ability to make things:
"Is it his immortal soul, his rationality, his self-consciousness, his free will, or what, that gives him a claim to this rather startling distinction? A case may be argued for all these elements in the complex nature of man. But had the author of Genesis anything particular in his mind when he wrote? It is observable that in the passage leading up to the statement about man, he has given no detailed information about God. Looking at man, he sees in him something essentially divine, but when we turn back to see what he says about the original upon which the "image" of God was modeled, we find only the single assertion, "God created." The characteristic common to God and man is apparently that: the desire and the ability to make things." (Dorothy L. Sayers, in The Mind of the Maker)
Humanity has been given stewardship over the planet (and we are accountable to God for that; it is just and right to treat our resources as the gift from God which they are, entrusted to us not simply for our lifetimes but for the lifetime of the planet, or as long as He leaves us here) as well as authority over other forms of life on this planet. So how do we exercise that? On a very basic level, we are called to learn, to grow, to make good decisions. Proverbs 25:2 says, "It is the glory of God to conceal a matter, But the glory of kings is to search out a matter." God conceals things, placing them in such a way that the noble, the diligent and the curious may find them, might figure them out, might see the hand of God in His creation and learn more about His character.
YHWH's handiwork, the space-time continuum, is big - we're just beginning to suspect how immense it is. Our galaxy is one of billions within this expanding universe. Our sun isn't very large, our planet isn't very big (but it's distinctive in some interesting ways), and we are small creatures living and moving on the surface of this sphere, spinning in space, orbiting our sun, moving along within this spiral arm of the Milky Way, one galaxy of billions, the scope of which we cannot grasp—and yet, "what is man that You take thought of him, And the son of man that You care for him?"
When I consider Your heavens, the work of Your fingers,For reasons beyond our capacity to comprehend, God loves us and chooses to interact with us, to an extraordinary degree. I can understand why atheists think Christians and Jews are deluded, why they think we suffer from a strange kind of narcissism: "even if God existed, why would He care about you, about us, about any of us? We're specks of dust." We are dust; God says so in Genesis 3, "For you are dust, And to dust you shall return.” But we are dust known and loved by the Maker of the Universe, dust with which He identifies to the point of incarnation - how it boggles the mind! For those of us who have responded to the call of Jesus, Yeshua, we cannot deny the reality of God's interest in us, His amazing love for us, even if it makes us sound like narcissistic dust.
The moon and the stars, which You have ordained;
What is man that You take thought of him,
And the son of man that You care for him?
Yet You have made him a little lower than the angels,
And You crown him with glory and majesty!
You make him to rule over the works of Your hands;
You have put all things under his feet,
All sheep and oxen, And also the beasts of the field,
The birds of the heavens and the fish of the sea,
Whatever passes through the paths of the seas.
O YHWH, our Lord, How majestic is Your name in all the earth! (Psalm 8:3-9)
Photograph of the Milky Way from Joshua Tree by Rogelio Bernal Andreo at Deep Sky Colors.