The word image in the Hebrew בצלמנו in v26 speaks of being a representative form, like a shadow. It takes on the form of the original and is intended to imitate the original.
In all instances that the word tselem is used, its always a representation of another. The vast majority of the times unfortunately it is an inanimate object (idol) representing a deity, unlike the case of Adam who is a living image(r) with responsibilities.
The LXX in this verse uses the Greek word εἰκών for image and the word can be understood to mean a copy. God made a copy of Himself in Adam.
For the law having a shadow of good things to come, and not the very image of the things, can never with those sacrifices which they offered year by year continually make the comers thereunto perfect. Heb10:1
This verse seems to indicate in the NT Greek usage of the word that the image is a good copy or a good representation of the original unlike a shadow which is too vague.
Its followed by the word translated likeness כדמותנו to further explain and build on the idea that it’s about being similar to God.
This word demure means, similar or like but not the same as, in all other instances it is referenced in the OT
It would at first impression appear that this is referencing the physical appearance and this might includeinclude the physical appearance yet is not limited only to appearance but it especially means to be a representative in likeness to God. A copy of God on earth. (This only makes the nachash’s offer to Eve all the more enticing, don’t just be a copy of God but be a god in your own right).
However the Hebrew continues to speak of dominion וירדו and if one were to take the translation punctuations out, one could read the text as saying something to the effect, ’let us make man in our image and likeness with dominion over the earth‘
In which case the emphasis doesn’t fall so much on the exterior appearance but the position of authority. Man was intended to govern on the earth as God governs in the heavens.
Man is the imager of God, like a representative or in modern language like an ambassador of God on the earth, exercising dominion over the realm below the firmament