Thanks George for coming back to this thread you originally initiated!
In my view, Genesis 5:1-3 clearly confirms that “image” means a “reference to physical appearance”.
Indeed, one has always to keep in mind also Genesis 9:6:
“Mankind” is and remains “in the Image of God” also after the Fall.
Accordingly, “Mankind” is in God’s likeness and after God’s image, the same way as Seth is in Adam’s own likeness and after Adam’s image.
A straightforward way to make sense of all this is the following:
Seth is after Adam’s image because both share the same type of body.
“Adam” (referring to the first accountable corporal creatures) is after God’s image because “Adam” shares the same type of body God chooses and shapes to become flesh (incarnate). By this choice God defines humanity: God calls the first accountable corporal creatures “Mankind” just as Adam calls his son “Seth”.
Accordingly, it is Jesus Christ’s flesh which defines the human flesh and body
We are human not because we are genealogically descended from Adam and Eve, but rather because we share the type of body God prepared (through evolution) for His Son to incarnate.
Notice that this explanation does not bear any “Tasmanian problem”: Tasmanians (like other possibly extant uncontacted peoples today, even aliens) are human and deserve the dignity referred to in Genesis 9:3-6, not because they are genealogically descended from Adam and Eve, but because they share a body like Jesus Christ’s body.