Nothing, as we know for a fact time travel is a thing in the Castlevania timeline , ah!
This. By this point magical time travel is clearly established in the series. Which isn't surprising as magical time manipulation has been present since literally the beginning.
So I am going to go more obscure and say the clocks in LoI. Mechanical clocks would not be invented for another 550 years. So unless Walter causally time jumped to pick up furniture for around the house, I don't buy it.