What side B really means

I saw a lot of people saying theories about this and i think i know what really means, so in the noelle weird monologue she says she wants to go to the other side, the side B, and at the end of the chapter it says Insert chapter 7 side b, so this meand that the chapter 7 will be in the lake, maybe starting in the lake, or having a dark fountain here, or the lake being important or something. On the normal route the chapter 7 will be in the side A of the lake, and the weird route in side B (The other side of the lake)