Commentator: "She's focusing on what's happening under the water and obviously, that's the only thing that matters."
Yes, the only thing that matters in this race to determine who is fastest. See attached screenshot...this is a fully unnatural body position that no one should try to emulate on purpose. Lots of swimmers will be "double jointed" with lax shoulder capsules and can get away with swimming this way.
Janet Evans is probably the only person in the world who can STILL SWIM after so much training with stroke. She is an anomoly just like Sun Yang is. SUn Yang's stroke is much more teachable and sustainable for the majority of swimmers, especially adult onset swimmers.