He looks like a relatively normal human being. Which is amazing for his character. We like to think of things that are evil as different from us. That's why Darth Vader had a mask, Sidious had a destroyed face from force lightning, Maul was a red and black alien with horns. But Kylo Ren becomes much more when he removes his mask. His not an evil creature or a monster. He's a person. A normal looking person, and I think that symbolism is fantastic.