Lol, thats not a strong jawline. He's sticking his chin out in both shots. His jawline is pretty average. If they can prove me wrong by giving a helmet without chinstraps that doesn't look silly, then good, but I think the chin strap accentuates his jaw
I prefer this
That concept art up their would be perfect IMO, if it had some sort of chinstrap. It makes the helmet pop more a little more.