Ok, I've been rereading and the chapter where Grimm meets Folly and Master Ferus for the first time is full of interesting things. I'll post a few in a separate thread but this one deserves its own one.
I remember in my first reading to have read that in the TAW world there is a moon. I specially noted it because of course no moon or 2 moons would have indicated there is no chance TAW happens on Earth. But in this chapter, Grimm mentions the mural that seems created by a child. It's all colorful and it has many unknown creatures and a moon too big for the sun. I was thinking. Could it mean that the TAW world is another world, but the aetherealists remember/know about our Earth? Or TAW is Earth so many years in the future than the moon is farther away from Earth? Other options, besides "it is not important, it is just a drawing?". For instance, atmospheric changes making the moon look smaller in the TAW present?