Same Place Very Different Look

This abandoned ski lift building is a place that I have visited and done photos in many times.

It's a cool little spot for light painting or dark portraits, and even better it's very easy to get to/in.

But on this visit, it had a very different look! Flags were put up all through it, with an unknown symbol on them.

Then the small back room had a mural of Hatsune Miku and a makeshift podium with the same flags.

I honestly have no idea what to make of this. At first I thought kids or a photoshoot, then remembered that wall shelving units had been torn out, other things built, etc. Would have been a lot of work and would have taken a long time. Probably more than what any teenager or photographer would do. So I'm at a loss, and chalking it up to one of those weird things found while exploring lol.