I love the idea with flags! I googled and it seems it happened at least several times, maybe it's a regular thing, in the summer, when the weather is nice. I'll surely be looking for it if I'm there. Tourists from the entire world :)

There was one man who would not talk at all, he just took willing people and nudged their arms and feet and general body into a certain direction, until they stood in a very weird way, and then the man would insert himself into the pose, and suddenly it made sense, and someone else would do a picture of it.
It sounds really interesting. And different from anything I've seen being performed on streets.

Thanks for making this post :D