Left : Mountains of Youkai, where the river seems to come from. Basically where is the Moriya Shrine and the tengus.
Above it, the cloud tornado : the cloud route that leads our maidens straight to Byakuren Ship.
On the right : The cherish tree on top of the whale, with the giant city? Strangely, I would say it's Netherworld, where Yuyuko and youmu are. Explanation for the city?...Yuyuko and Youmu are not the only one who lives there.
Bottom right : I would say the forest of magic, but since that normally SDM is in the middle of the Magic Forest's lake...Or else I'm messing up and it's just some brushes.
At the center , a bit on the left : Cirno's bloomers.
Maybe this is how Cirno sees the world. As giant among mortals, Strongest of all she surveys, a more compact Gensokyo, since distance meets little to her...with inexplicable sky-whales showing up from time to time.