The word for “image” (selem) in Hebrew describes sculpture and clearly refers to, as David J.A. Clines says, “a three-dimensional object.”
As Daniel Boyarin notes, “God was understood as a being who could be seen.” There are many appearances by God as an embodied form. “And they saw the God of Israel,” says Exodus 24:10.
Here is a short bibliography of sources for you to consult.
David J.A. Clines, “Humanity as the Image of God”
David M. Carr, “Made in God’s Bodily Image,” from The Erotic Word: Sexuality, Spirituality and the Bible
Andrew S. Malone, “The Invisibility of God: a Survey of a Misunderstood Phenomenon”
Catherine McDowell, “In the Image of God He Created Them’: How Genesis 1:26–27 Defines the Divine-Human Relationship and Why It Matters,” from: The Image of God in an Image Driven Age: Explorations in Theological Anthropology
For a book-length treatment, try: Benjamin D. Sommer, The Bodies of God and the World of Ancient Israel