Cemetery keeper - function?

I noticed there is a cemetery keeper, but that it is not always the same sim. I think the current sim is one older NPC though, so I assume the game did not create them all new for this pack.

Anyone know how they are picked and what is their function? In a way I would rather see a non-played Undertaker at work at a cemetery. Then they would make perfect sense, both who they are and why they are there.

I've not yet seen the keeper performing any particular job, but I've not yet played a funeral.