We see what we expect to see

As we come into the Christian season which anticipates the birth of the baby Jesus, a dose of art history explains the mystery of why medieval representations of the holy child render him so ugly. Apparently the reason is theological, reflecting doctrine about the nature of Jesus.

Medieval concepts of Jesus were deeply influenced by the homunculus, which literally means little man. "There's the idea that Jesus was perfectly formed and unchanged," [art historian Matthew] Averett says, "and if you combine that with Byzantine painting, it became a standard way to depict Jesus. In some of these images, it looks like he had male pattern baldness."

Apparently it wasn't until much later that the adult Jesus came to be represented as a long-haired hippy.

Renaissance society adopted a novel notion of childhood innocence, so its representations, both of the baby Jesus and aristocratic children painted for wealthy art patrons, drifted toward saccharine and cherubic.