I managed to trigger the scene before I read your response but thank you nevertheless!When Rose is in the bathroom (between 14:00 and 14:30) you'll have a chance to peek on her, if you want to force the scene I recommend you to quick save (F5) before 14:00 (let's say 13:50) and then after 14:00 has passed, try the door, it can either show you the scene, or throw the locked message, if you get the message, just quick load (F9) and you'll be on the door at 13:50 again, if I'm not mistaken the chances are 1 out of 3 so you should be able to get it fast.
Looking forward to the next update and scenes with other characters. Fun game!