In a moment of political passion, a loyalist woman at the Belfast City Hall shrieked "No Surrender!" through a break in the glass of the back door and became a comic icon.
That image of her rebuking the city councillors through the door has been appropriated by humorists on the internet and become one of the enduring images of a week of protest.
This can't be what the protest organisers wanted. They will have planned that that night would be remembered for the large crowd that gathered and the flags they wore and wrapped round them, establishing forever in the minds of anyone who might doubt it, that the Union flag is loved and revered here.
Instead, the clip that is replayed in various forms is of that woman.
She has been cut into video remakes of the shower scene in Psycho and the moment in The Shining when Jack Nicholson's mad eye appears through the crack in the busted door. "No Surrender!"
Humour prevails here even when people are worried. That cry through the door marked the start of a week of protest over flags which has brought masked men onto the streets and seen rioting close the city centre. No one yet knows how the stand off will be resolved, but hey, you have to laugh!
And that laughter is the familiar backdrop to many of the grim occasions during the Troubles.
However intense the sectional passions have been, there have always been jokes.
Some of that humour has been grim and savage.
Both republicans and loyalists, going right back to the 1960s were publishing their own cartoons and writing their own songs.
Even at the heart of their traditions there was an element of self mockery. How else do you explain a song like The Pope's A D**kie? At first it seems like raw sectarianism mixed with racism.
Listen to its jaunty beat and you realise that it is taking the mickey out of sectarian attitudes that would have been strong among the audiences who were tapping their feet.
Gregory Campbell MLA for East Londonderry used to sell fun items from his stall at Orange parades. These included bibs for babies that read; Born To Walk The Garvaghy Road and signs that read, Keep Ulster Tidy: Dump Your Litter In The Irish Republic.
Those were in the days when you could buy William of Orange Marmalade at Ulster Unionist Party conferences.
Some of the humour is vicious and some of it is 'knowing' and even self-deprecating.
The loyalists sang, Would You Eat A Pastie Supper, Bobby Sands? This was to annoy republicans who revered Sands and his hunger strike sacrifice but it was also to undermine the sense that Sands was making an important political gesture that we had to take seriously.
Something similar is happening in the joke-making around the woman who shrieked "No Surrender!" through the broken door.
Whether consciously contrived for that effect or just by accident, it deflates the impression of an ardent and conscientious political movement.
It caters for people who would rather laugh than be afraid.
The mystifying claim by Councillor Ruth Patterson that Republicans burn the Tricolour at all their parades has the same effect.
It reassures us that these people are stupid and don't need to be taken seriously - which may in fact be a serious misreading of them; we'll see.
But the loyalists are getting their own back.William Frazer of campaign group Fair posted on Facebook yesterday a picture of the sign for Raymond McCreesh Park with a new name, Oliver Cromwell park.
But there is another element in the humour about the flags protesters.
It is driven by a sense that the people protesting are themselves laughable and pathetic.It fits in with a strand of Belfast humour which mocks working class and poor people, those who can, for some, be dismissed as spides and chavs.
The implication is that people who dress and talk in a certain way don't need to be taken seriously.
You don't even have to stretch yourself to make a joke about them because they are inherently funny.
This is the contemporary expression of class consciousness in the city and there is nothing decent or sensible about it, just the smugness of those who are relieved to be better off.
Yet this parodying of the poor goes back a long way too, and there is a strong element of it in the humour of The Hole In The Wall Gang, even going back to Jimmy Young. It is so ingrained that people think that a Belfast accent in itself is enough to raise a laugh or let you down.
We should think more carefully about what is going on here.
For if the new loyalists on the street, in their masks and hoodies and with the flag wrapped round them are just funny for being themselves, for being poor and ill-fed looking and sounding like they've never before had to think carefully before speaking, then the joke is a poor one and misses the point: that they are a problem because they have a problem, whatever it really is, whoever it is that will one day be able to articulate it for them to us.