This is a very well designed house. It's also clearly somebody's home, rather than a sterile house only available for short term lets. That means that you do have a little of the clutter and bits and bobs of a home. This gives the place character.
I'm going to suggest to the owners that they create a little handbook for the house, detailing where to find things, and what can and cannot be played with or used, so as to give clear limits.
I'd also suggest that because of certain things in how the house is laid out, that it isn't suitable for families with very young children, or poorly disciplined children - there's an internal mezzanine area which daft kids could get in trouble with.
There are two lovely cats that live outside who have adopted the house. You can feed them and water them, or the owners will come and do so. We didn't mind feeding them at all, but I imagine some people might. It's also nice if staying to sometimes water the potted plants - the place is really like an oasis, and as somebody staying it's nice in a way to be a part of keeping it that way. I may have actually overwatered the lawn as it grew up quite a bit while we were there!