And more often than not in films, such as the Brit melodrama below, they stand in as a safety mechanism which points such tensions away from the rest of the film/book/painting into one or two containable instances of showing "the people."
(Note: In film below, for instance, one of the functions of this "scene of the people" is as a container, one which ultimately fails, not necessarily of communistic elements but those which more generally are insupportable to an order of the management of the social. Such an instance, of excess and punishment, helps to to point away from, for instance, the deep pleasure of illegality and the fact that the entire film is so turned on by itself that it doesn't even bother with double entendres. It just goes for single ones. I mean, one would never say that if one was actually talking about eating to the point of being too full. I began to suspect that the entire British libidinal economy allotted for about 15 years was blown in full on this film. After these heights, nothing can remain, other than a still camera framing two gray-faced people eating porridge at a table and talking about marriages that failed but stayed together to save on rent.
More specifically, the deeply kinky and quite startling moment where the mixed-up couples, stuck in the wrong arrangement and unable to change it for reasons of scandal/Margaret Lockwood tending to murder those who get in her way, suddenly realize: wait, this is seriously idiotic, and we're treating each other horrible. So screw it, let's go ahead and all four of us live in this big house together, technically married to the wrong people but leaving behind any linkage of state/social recognition of coupledom and actual affective bonds, and free to fuck in whatever combination seems right to us.
Spoiler alert: if the film actually allowed this radical outcome, rather than deviating into mistaken identity and bullets lodged into stomachs and once again Lockwood dying on a carpet, with camera angled down at her, in a large stone room for the second time in two years, if it actually had allowed this, we could be damn sure that the "free choice" of the swinging parties involved would have looked very heterosexual and very monogamous.)
Very well. For this reason, let's start by taking them at their word and winding through these instances...]
Reverse tracking shot from prefiguration, as gibbet toy and broken neck floppy rabbits, through the rabble and the carnivalesque (following the previous actual carnival sequence, which ended with a massive roast pig, a precursor echo that sets expectation for the film: motley mixed class crowds = hunk of dead flesh at jubilant center), out to frame the material support for the occasion that brought together such a toy and such a crowd, the crowd whose subsequent rioting will cause such disarray that the hanged man will not be fully hanged, cut free by his friends and brought back from the almost dead.
The prole crowd gathers for a hanging in order that such a hanging will not succeed.