Ozu is a master of occlusion. It happens on two levels: the spatial (frame) and the temporal (arrangement of frames).
The tatami shot expresses occlusion at the spatial level.
Either there is a tatami shot, or there is not.
Either the tatami shot is replete with empty space, or it is not.
Empty space adds the primary layer of occlusion. It creates the distance between the viewer and the characters. In an emotionally heavy scene, where an explicit close-up happens to be the immediate choice, the distance refuses immediacy altogether. As a result, the affect has no choice but to leak into the empty space. It morphs itself into the atmospheric, the space heavy and intense. If there are entities present, the layers of shoji, the low tables and chairs, a layer of explicit occlusion is added. Now the air has to maneuver through objects, take turns at screens, and set itself on the correct course. A case of spatial occlusion with something extra to it.
“The father and daughter are preparing to spend their last night under the same roof; she will soon be married. They calmly talk about what a nice day they had, as if it were any other day. The room is dark; the daughter asks a question of the father, but gets no answer. There is a shot of the father asleep, a shot of the daughter looking at him, a shot of the vase in the alcove and over it the sound of the father snoring. Then there is a shot of the daughter half-smiling, then a lengthy, ten-second shot of the vase again, and a return to the daughter now almost in tears, and a final return to the vase.”
Transcendental Style in Film. Paul Schrader
The pillow shots allow occlusion at the temporal level. Consider the vase shot. The heavy emotional transition that Noriko takes is dispersed temporally by the standalone vase. Each time the affect appears, it is temporally occluded, allowing it time to linger, expanding the temporal existence of the affect, and a binary (it is/it is not) that increases distance between the audience and the affect.
However, the subject matter (the other member of the hylomorphic duo) is extremely boring. It is unclear to me why I should care about the repressed incestuousness in conservative families and cultures.