The live stream for Chapter 3 showed it as having the ability to place a thrall in it, similar to the bar. You take one of your own placed thralls and put it inside when it highlights green. However, given the fact that some of the other objects like Yamatai pillows and the cooking spit (i think?) don’t work this way yet, it’s possible it may not work currently. I couldn’t tell you since I haven’t bought it yet. That being said, it SHOULD work as intended, if not now, eventually.