Note: This achievement can be unlocked only during or after having played through Dolores' chapter, as you must have access to the attic.
Once you have access to the attic, there will be a glass display case in the middle of the attic. Inside of it you'll find a square piece of paper with a smiley face on it. Move around the display case to get to the open side, and pick it up. Click again to make it glow and disappear, and the achievement will pop!