In Universe Attributes
Real World Information
Unlike most Loops with sections, there is only one Anchor that bounces between the two of them, with them serving more as alternate baselines than anything else.
The first Gensokyo, where the Hakurei Shine is inhabited by the spirit known as Mima, with the angel of death Sariel and the godess Shinki serving as antagonistic forces, along with other such beings that do not exist within the modern Gensokyo. Perhaps the biggest difference is that it is a completely seperate world of its own, and is connected to a number of other realms that do not even exist in the other baseline.
Having been hidden from the technological world by Yukari due to the lack of belief in magic weakening the beings who use it, this Gensokyo is more or less the true baseline that Reimu will Loop into nine times out of ten, and has a larger Looping population because of it.