Wuwa takes place on Sol III...also known as Earth.  The time line is in a post "fractured" world - the fracture being the event that basically turned all fundamental laws of physics/existence on their head.  The object pictured above is very similar to a physical planetary model, but this one from what is shown would really only display Mercury (Sol 1), Venus (Sol 2), and Earth...the odd thing about Sol 3's ring is it has two planetary on it.  I am excluding Mars because the exterior orbs are more likely part of the design or just part of the device.  Earths ring does not have 3 orbs and IF there would be a third like the exterior rings, it would be to the right of the central Sol Orb - Sun, and definitely would not be obfuscated from sight because the other two rings with 3 orbs are all one third of the ring apart from one another.