He looks Italian.
It was an Italian computer..............
It's the nose. I attended a lecture by a local professor who stated that the Man of the Shroud had a break in his nose, NOT THE BONE, but the cartilage that extends past the bone. This gave the nose a somewhat crooked appearance. The renderer didn't seem to take that into consideration, probably not wanting to deviate too much from the Shroud itself. Stretch the picture a little, cover the nose a bit, and he actually does look like a young, handsome boy. A straighter, shorter nose would have been more age-appropriate.
Being Italian myself, I thought as you did: I had a little button nose as a kid; it didn't look more pronounced, ethnic, until I got older. Same with everybody I grew up with, I guess...