Well, due to the massive gravitational lensing from the intermediate galaxy a few billion years away, I guess it's not actually a perfect 13½ billion light year

Well, due to the massive gravitational lensing from the intermediate galaxy a few billion years away, I guess it's not actually a perfect 13½ billion light year sphere right... It's a fair chunk of the photons in the 10 billion light year sphere swept up and focused over a vast area and pointed in our direction. Still amazing to think about though.