Les commentaires sont HYPER intéressants pour voir les jugements de valeur sur "les origines" en France et l'utilisation des drapeaux dans les bios twitter. Il y a même des gens qui ne comprennent pas le métissage. https://twitter.com/imbesst/status/1285119321803501569

Some analysis on this:
1) The joke in the first tweet is that someone with two French parents puts a Colombian, a Korean, and a US flag in their bio. The tweet is mocking this fictional person (who is representative of a phenomenon on Twitter) for trying to seem cool or cultured.

Why these flags? Netflix. The most popular series with Gen Z are thigns like Narcos, K-dramas, and US high school dramas. Although the person's family ethnicity/nationality is 'boring' (French), they use flags from 'interesting' countries, but end up being another cultural sheep.

2) A lot of comments agree, but diverge away from the initial premise of the joke to talk about 'basic' people (perceived as monocultural or monoethnic) exaggerating their non-French cultural ties to seem more interesting. This is judged to be pathetic and attention-seeking.

3) There's an especially interesting analysis of French people trying to claim NorthAfrican heritage via either a pied-noir (white settler) family member by marriage, or a distant NorthAf family member. This reminds me of US citizens claiming to have a Native American ancestor.

Being visibly NorthAf or Muslim in France is a source of discrimination, but this identity is also exoticised, and publicising one's connection to it is seen as trying to make one "spicier" and more interesting.

4) However, the opposite is also criticised: people with exclusively NorthAf heritage trying to westernize themselves by adding a Canadian or US flag simply because they have a (possibly unrelated) family member who lives there.

5) Beyond the judgement of mixed race people and poc, there is also a judgement of white people with diverse heritage. Someone asked how it was possible to have flags from 5 European countries in their bio, and other users had to explain how all four grandparents can come from...

... different countries. Although this thread is mainly people who are minorities in France judging each other and the majority, there are also people who have apparently no idea how a multicultural family/person could exist.

6) Finally, we see the judgement that a French person who posts a French flag in their bio is probably a racist, and that French regional minorities (like Breton and Basque) can't wait for a flag of their own to post. Perhaps the co-opting of the French flag by nationalists...

... is a factor that pushes monocultural French people to "spice up" their family background or place more of an accent on it. I'd venture that in the English and German flags have much the same connotations.