It's in the room on the 2nd floor that has two holes in front of it :) To access it talk to Sasha in the kitchen then grab the axe hanging on the wall, cut the wood near the warehouse and interact with the holes
I asked Sasha, cut the wood and went upstairs as you said then go to the holesafter going through the mirror I checked each room and interacted with the objects but everything was the sameThese are all the items that I havei'm wondering if i did something wrong :"((((