UMM.. WHAT IS THIS?!

Ok, so I was putting all my artwork I just bought in my den, when I accidentally scrolled into this hidden basement with CAMERAS?! Am I just oblivious to the fact that this existed? I can’t find an obvious entrance to get to it which is why I’m so confused. The den is called the magnificent mansion, go try it for yourself. All you have to do is scroll with the camera just like I did until it takes you there. WHY ARE THERE CAMERAS WATCHING MY DEN?! HELP 😭