You Can't Turn Around
In the game, make sure that you have fully explored a room before you complete your next objective. In most cases, once you continue on, you'll be pushed through the story and won't get a chance to return to the room, so any undiscovered secrets or pictures will be inaccessible.
re paths and you won't know which one will progress the story and which is for exploration. Or, you may be timed without knowing it and will be booted into a cutscene after a certain amount of time. In these cases, there may be nothing you can do about it, but take your time and don't push ahead blindly before you've had a chance to look for secrets. Thankfully, the slow walking pace of the exploration parts will aid you in this endeavour.