Nothing. The artist conceptual photo didn't change the Scharfenberg couplers as seen on the original Alstom equipment to a US standard knuckle type. If it came to fruition that they did use this equipment in the US, they would most certainly need to have AAR type accepted couplers, or at least an adapter on board on both ends.

Also, sure, the European type train sets need modification to be AAR compliant, but I also believe that their signaling systems are far superior to what the US has in regards to something a little closer to fail-safe, as well as more grade separation for crossings to the point where the structural modifications are not necessary.

I am referencing ERMTS, KVB, and ATC here.