The point is just to have fun. People enjoy building things. Did you see the sandcastles at the beach party? It's the same principle, only that this snow will also cool people down in the summer districts.

...

Can I put your bird on my mayonnaise bottle?

[If Eren agrees, he's place the little snowbird on top of the snowbottle and use a tiny, brief flame to freeze it in place. Now it can see better! (Hijikata's playful side rarely comes out, but apparently this is one of the times it does.)

As they sit by the campfire to eat, the sun goes down, and while the shy isn't entirely dark yet, a faint glow appears in the north. With a little luck it'll intensify as night falls, and Eren may get to see the real northern lights after all.]