I was confused also but I think what is being said here is that "noon" is de-coupled from "12:00" and becomes relative to the local position of the sun. So if you are at UTC-4 today your "noon" would happen at at 8:00 and if you were at UTC+2 your "noon" would happen at 14:00.
Honestly I had a hard time even figuring that much out. Time is hard.