Maybe a prank?
Maybe just not quite thought through.
What, is there a bucket of water on the top of that door or something? Because otherwise all you’ve done is make it easier for someone to enter the room.
Or is that how you think that water-gag happens? Because you’re too short to reach up there, do you think that just by leaving the door a little ajar will make a bucket of water appear there?
You’re not very good at this, Penguin.