It appears to be a large stage serving as a kind of elevator. But it can't go down because there's something jammed in it. Looks like a peculiar musical instrument, probably centuries old.
But yeah, the jury agrees. You've got to go blow up those trespassers.
Hey check it out. Every week we'll be revealing some new troll characters from Hiveswap until Act 2 is out. Follow the Troll Call here, and meet the first two here. Expect a few more surprises like this to drop in coming weeks.