After you escape the apartment and go  back to the mansion, there's a metallic shard in Anne's (Body/Corpse) if you take it and go to the pedestal (or altar idk what to call it) you can insert it, and see some extra content! (sorry if this is long) 

Oh and also, the game was great I really enjoyed it the graphics were good and the story was even better!

Glad you enjoyed it :D There are more secrets to be found, if you are willing to give it a shot ;)