Shack is also part of chapter 2 in Criminal Case - Case 3. This games is absolutely one of the best games online today. Below are the things that you need to search in the scene. Also the hints are there:
Dog dish - South East on top of blue thing
Tentacle - North West
Picture frame - North East
Bloody rag - West - roof top
Tic-tac-toe - North West On Roof
Aerial - Middle on top of that red cabinet
The bloodstained Rag will be the clue for this scene.