A Rose in the Twilight

At Library 4, there is a portrait you need to complete by placing a bloody chair in front of it. You can find the chair on the right, near a fireplace with a red banner above it. Don’t pick the chair up yet. Switch to the Giant and stand on it, then grab Rose and throw her against the banner above the fireplace. If done correctly, Rose lands on a ledge and is able to continue to the right. Proceed further until you find a dead cat, pick it up and go back to Giant. Afterwards, you can interact with the fireplace and cremate the cat. This will get you the trophy.