So, I just finished playing Episode 4 of TWAU on my second save, because I can't get over the fact tat I won't be home for the finaleon Tuesday, so I played. I noticed something though and I don't know if it has been mentioned by now, so sorry if I repeat anyone.
I chose to go to the Cut Above butcher shop second and yeah, I went to the secret back room where the illegal glamours are made. When you go around and click on some boxes on the left on the board, you actually get to ask what the symbol on them means.
Yes, I'm talking about the symbol that we all know and "love".
When you ask Johann about it, he explain that it is a torture device which brakes people's bones and makes them "crooked".
And look what we can see in the trailer for Episode 5: I stronly believe that this is the exact torture device. And I think it will be tested on someone and I don't want to know who it might be.