This person found a way to let people know there is no more toilet paper
Using a toilet roll, this person left a humorous reminder. At the very least, they were thoughtful in doing so. They may perhaps have simply left it where it was. While clever, this is a little unclean. However, this is a terrific way to let people know the supply is done.
There is nothing more annoying than going to the toilet and finding out there is no toilet paper when it is already too late. If the finished roll is not being immediately replaced, then an excellent hack would be to leave the empty roll between the bowl and the lid for others to see next time they visit the throne.