The Eclipsing Heaven had half-turned around at this point with the side where people lived beginning to experience morning. The soft glow of the atmosphere that domed around the realm scattered a few rays of light toward them, letting them see what it was.
The scene itself was amazing incredible, but it was the rest of the realm that fully caught Alex's attention at that point.
The Eclipsing Heaven realm was not thin by any means. Alex had thought of realms as similar to plates, maybe thicker, with people living on one side, and the other side being empty.
He was correct that it was empty everywhere else. What he was not correct about was the thinness of the realm.
The realm was by no means thin at all. In fact, it could even be considered quite thick.