The image of God in man (Gen 1:26-27) is an important concept. In some way it distinguishes man from the animals. It grounds the prohibition against murder, and singles out the fitting punishment. Yet because the narrator doesn't define this category, it has spawned a vast theological literature of competing interpretations. In historical theology, it becomes a cipher for whatever theologians happen to to think distinguishes man from the animals, viz. rationality. More recently, you have functional as well as ontological interpretations.
Some scholars distinguish between "image" and "likeness", but I suspect that here they are synonymous. A pleonastic expression for emphasis.
On the face of it, the image of God presents a paradox: given Israel's aniconic piety, how can man be an image of an invisible deity? The very fact that the category is undefined suggests the narrator expected the target audience to be able to figure out what it means. There are two ways that could be. It could play on extrabiblical associations that were familiar to the target audience. Or it could play on intertextual associations. Genesis is part of a literary unit: the Pentateuch.
Nowadays, one popular scholarly interpretation is that in the ancient Near East, the statue of a king or statue of a god stood for him. It represents his presence. It doesn't necessarily reflect his physical appearance, but his prerogatives. By analogy, man is a representative of God on earth, acting in his stead.
This may be a perfectly adequate interpretation. I would, however, like to explore an alternative interpretation. In the Pentateuch you have angels. There are different kinds of angels, or angels under different aspects.
With one notable exception, angels are a class of creatures. They vary in appearance. Cherubim (and seraphim) may have multiple wings and multiple faces.
By contrast, you have humanoid angels. Outwardly, their appearance is indistinguishable from humans. In addition, angels can become luminous.
Finally, you have a theophanic angel: the angel of the Lord. That's not a creature, but a local manifestation of Yahweh.
The theophanic angel has a humanoid appearance (e.g. Gen 18), but it can also become luminous (e.g. Exod 3). The "burning bush" is something of a misnomer. The bush was never on fire. It seemed to be on fire due to a montage between the bush and the luminous angel.
Here's my point: human males resemble God insofar as the theophanic angel resembles human males. In that respect, the image of God could have a visual counterpart. It isn't necessarily just symbolic. To be made in the image of God could mean (at least in part) to resemble God insofar as humans look like the angel of the Lord. In that respect, there could be physical correspondence insofar as the theophanic angel assumes, or simulates, audiovisual and tactile properties.
There's also an argument to be made that the theophanic angel is a Christophany. If so, it foreshadows the Incarnation. If so, it represents the culmination of this theological motif. On the one hand, Jesus and the theophanic angel are both divine. On the other hand, Jesus and man are both human. If the image of God is defined (at least in part) by reference to the theophanic angel, then Christ unites the twofold significance of that category in his own person.