Shifting ground may mean something like the following. Neo-noir story-telling is fond of ambiguity and leaving the viewer in the dark for considerable periods of time before clarification arrives. This creates uncertainty in the viewer. Some of these films are fond of multiple twists near the end. The result is that you may never know quite where you stand or what you conclude about characters for a considerable period of time. The character that looks bad may suddenly appear in a good light and vice versa as you learn a critical piece of information.
Instead of time inversions and flashbacks, although still prevalent in many neo-noirs, one may see character inversions. The ground shifts.
The stories are being told in more disorderly ways too, and that creates a sense of loss of order too. The narrative flows and cutting are more chaotic.
Most of this is not in the neo-noir-o-meter categories.
"The Master" has a significant taste of absurdity. It's not exactly surreal but you have to say it approaches being surreal. Making booze from a torpedo's propellant or drinking a bottle of after-shave or an old man dying from drinking the concoction followed by a foot chase, the antics of Dodd, even the way Quell manhandles Dodd's critics -- all of this is more like a Keystone comedy than anything real. It only earned 5/5 points from me. Perhaps black humor needs to be raised to a 10 point category. That would take in a very large number of neo-noirs.