I have no idea. The Bible doesn’t give us much to go on, except that he was Jewish, and did not stand out from anyone else in appearance. In the picture the girl painted, she used an actual man for a model, who just happened to be a young Jewish carpenter who showed up at her door. After she prayed for a model to use that looked like the Jesus she saw in her NDE. You don’t have to believe that story, but if anything, if you’re going to imagine what Jesus looked like, it was probably like a young Jewish man.