Ozu’s most endearing characteristic, for me, is what Sato calls his "pillow shots." The term comes from the "pillow words" used in Japanese poetry – words that may not advance or even refer to the subject, but are used for their own sake and beauty, as a sort of punctuation. In Ozu, a sequence will end and then, before the next begins, there will be a shot of a tree, or a cloud, or a smokestack, or a passing train, or a teapot, or a street corner. It is simply a way of looking away, and regaining composure before looking back again. (via)

Ozu’s use of "pillow shots," which unobtrusively break up the action and give the viewer a moment to contemplate or rest. The "pillow shots" consist of flowers or banners or whatnot … (via)

Much has been made of Ozu’s visual devices: the camera pitched to the eye level of an ideal spectator watching from the comfort of a tatami mat; the compositions that emphasize the geometric qualities of the Japanese interior, with its clean lines, right angles and frames within frames; the "pillow shots," as Ozu called them, of wind-rustled trees, passing trains, empty side streets, that provide buffers of silence and reflection between dramatic scenes. (via)

Ozu also developed a curious form of transition, which various critics have labeled "pillow shots" or "curtain shots." Between scenes, he would always place carefully framed shots of the surroundings to signal changes in setting, as well as for less obvious reasons. Basically a hybrid of the cutaway and placing shots, these transitions were considered unusual for extended length; they sometimes seem motivated more by graphic composition and pacing than by the demands of the narrative. (via)