Thanks for bringing up the typo, I just corrected it.
The weird bullet catcher thing is a heavily edited picture of an "horreo", a typical rural building in Galicia that's used to store grain.
As for its significance, it's seen as a symbol of rural life around here so it made sense to have it contribute to massacring the corporate assholes. Also it has a shape that's fairly simple to put a collision polygon around.
...I just realized now that a structure for storage stores bullets in the game. I actually didn't plan that, but I'm going to pretend I did because it feels clever.