I'm afraid we're going to disagree again
Mumblecore is totally about the look. There's a reason why almost all the films that I've seen by people on this forum couldn't be bracketed as mumblecore. They're trying to put across a story with limited resources, but it doesn't turn out as mumblecore. Mumblecore as a movement may have started as a way to do something different with low budget movies, but you look at the resources and backing the Duplass brothers get nowadays and then ask yourself why they are still producing things in the same style they had when they actually had limited resources.
I'm firmly off the impression in film that if you can categorise a group of films into any technique then that technique is deliberate. And, I would emphasise, I have nothing against some mumblecore films, but it is a very easy thing to get wrong.
The Duplass Bros. are not making mumblecore anymore.