I think I get it.. maybe
The idea of it, is art
To appreciate the beauty in every day moments
He filmed his lover sleeping for 5 hours
I can appreciate watching my wife sleep peacefully for a few moments every day
Is the film actually worth watching? No, not really. It is just 5 hours of a guy sleeping, I would not ever suggest sitting through it.
But the concept behind it is meant to inspire introspection and reflection on the simple things, that in itself is artful
But on any level of reality, hearing about it has more inspiration than actually bothering to watch the thing for more than a moment or two. It's the kind of film you can leave looping in an otherwise static art gallery
I don't believe its really intended that anyone sit through 5 hours of the thing
Even if you wanted to spend time watching someone sleep, I think you would find more value in watching someone you care about and not a stranger