From Baharen Phir Bhi Aayengi (1966) / Shaheed Latif:
At the moment of the beginning of the song's performance, both the sisters are in love with the same man (he plays the piano like someone kneads the dough). In a manner that belongs very much to Bergman, both of them project their feeling of entitlement to such a luxury ( being the object of love of a man) very aggressively onto the whole situation. Neither is willing to concede any ground in this ménage à trois (more sexual than it is spiritual) - both demand their own respective close-ups, their private eyeline-matches with the actor and their very own, astutely choreographed, set of gestures (the first flutters an eyebrow, the second twitches a lip; the first betrays a cutesy grin, the second blushes a black-and-white blush etc.)
What is interesting too, ofcourse, is how the scene is directed to play a willing audience to their wholly presumptuous universes of a privately blooming love (entirely hypothetical at this point too - what if he doesn't love either?) - the camera lingers on the first, and then on the second, with the meticulously created impartiality of a newly elected leader who wants to be 'there for everyone'. Both are permitted an audience, as also equally divided immutable time-slots reserved exclusively for an individual performance.
As it stands, the picturisation itself becomes almost entirely about the act of 'looking' - as such, the scene becomes an assortment of fleeting glances, moony-eyed glazes, and rather intrusively-affixed stares. The song itself becomes the permeating fiber that is the basic material for this network of 'looking' - as the actor begins to sing, the camera dollies out, his voice being projected into meaningless vacuum, until the members of his audience are revealed through a cut : the sister-duo, at which point the camera dollies-in; thereby forming a system of projection-absorption of the actor's song.
Ofcourse, it is also at another level about the confusion inherent in an eyeline-match : if used well, such as in this case, you may not know exactly what the actor is looking at - the sisters are confused themselves (or are, unarguably clear who the song is being sung for) and their confusion transmits to the audience as well (if you do not know any better). In that, the editing becomes particularly essential too - because the shot of the actor looking in the sisters' direction is never followed directly with the close-up of one of the sisters, since such a schema will annihilate the ambiguity and reveal to us the object of his affection; instead, the reverse-shot of the shot of him looking is always a long-shot of both of them, which may then dolly-in to one of them, depending on who summons the camera first.