In this approximately 45-second long Lumiere Brothers actuality (Lumiere No. 82) we see two babies sitting in high chairs. They have fancy clothes on, and a number of toys in front of them, which they end up fighting over. Eventually the one on the left begins to cry.
Although Childish Quarrel (aka Babies Quarrel) is not nearly as interesting in terms of visual composition as many other Lumiere Brothers shorts--in fact, the framing of the subject is less than satisfying--the scene playing out before us is fascinating, funny and poignant. It says an awful lot in a mere 45 seconds.
The babies in the film have two very different dispositions. The one on the right is good-humored and (maybe too) rambunctious. The one on the left is fussy and obviously annoyed by the one on the right. Even though the babies are basically fighting over their material goods, we can tell that the right baby basically wants to play, whereas the left baby basically wants to be left alone. The right baby keeps smiling and laughing until the end, even trying in his way to console the left baby at one point. The film is informative in showing how instinctual certain behavioral tendencies and sources of conflict can be, whether the babies are acting surprisingly adult or adults tend to act surprisingly childish.
The short is also interesting for making clear that actualities/documentaries are not as "real" as they're portrayed in our cultural convention wisdom (I'd prefer to call it "mythology"). Childish Quarrel is obviously staged in that there was an effort to set the babies up in front of the camera in a particular way, close enough to each other, with a number of material items on their high chairs, so that they'd interact in a novel way for the camera.
Surely much of the Lumiere Brothers' work, as well as documentary material in general from other filmmakers, is likewise staged. As an artist, you want interesting visual compositions, interesting action in front of your lens, and so on. There is an effort in most documentaries to make the action look as "natural" as possible, or to encourage the "actors" to go about their business in the normal way, but there's an almost necessary interference by the artist which blurs the distinction between fact and fiction. Filmmakers working in fiction often want their actors to approach their roles in the same way. Backgrounds are filled with extras where the goal is to make them appear to not be extras, but "real people" doing "real things", naturally, behind the primary action.
Watching these early shorts is instructive because at the birth of film, artists were just beginning to sort out how to work with these ideas, so the philosophical and aesthetic points, which are just as present in today's films as ever, are made more transparent.