I want to give them the benefit of the doubt and say perhaps it's a deep freezer that is only opened occasionally, and I guess is pretty well sealed as long as it's closed.
The kitchen appears to have one of those built-in fridges that matches the cabinets:
Sorry everyone but you're all missing the obvious. You see that APPARENTLY there's no WC in the bathroom? Well there you go. When you're done, close the door, and it's nicely mimetized as a drying cabinet š
Or else, it's a civilised country when WC have their own space. And it's one of this house where, when you have the unfortune to live with your SO, you don't wait for WC because the bathroom is occupied.