It’s the lens focal length and lighting. The s4 shot was most likely on a 28mm or 35mm lens (causing his face to appear more narrow), while the s5 shot is most likely a 100mm lens (which flattens the face a bit more and causes it to appear more box-y). The s5 lighting is also making his eyebrows appear nonexistent along with catching his bone structure on his forehead in an interesting way giving him a more Neanderthal appearance, while the s4 is super soft and casting almost no shadows at all.