I am American (NOT Brazilian LOL) and will try to give you a fair shake despite all of the downvotes on your otherwise innocently “out of the loop on the topic of race” comments. This topic is a passion of mine and I’ve done a lot of work on it.
Whiteness is a British colonial invention which is why it is used in America - it was used in the census recordings of peoples in the colonies. The census being for figuring out where everyone is...and how to distribute resources to their communities. When the USA won independence they continued the use of the census. Essentially, “White” on the census meant being of British descent, or British mixed descent (think Anglo-Saxon English speakers). Other European immigrants would have their hailing country designated as their ethnicity, or actually “other” on the census. Over time, and after waves and waves of immigration, Europe-ethnic descendant families integrated to American lifestyle...and entered the “white” race category. There’s a great book on this called “How the Irish became White” about Irish-American citizens’ census categorization following the American civil war. Generally, you could argue that families and individuals being entered as White are the result of individual decisions every 10 years (when the census actually occurs) to report racial identity a specific way, and also the result of gradual societal changes that led communities to accept immigrants as countrymen. Or intermarriage. Or all of the other endlessly specific ways that someone might be considered a “White American” today despite genealogically being a mutt of English, French, Scottish, Irish, German, Turkish descent (this is me).
Americans are uptight about race, because we used to have legalized (police-enforced) discrimination based on race. That’s Racism. Being “Black” meant you could not, for instance, use the same public restrooms, water fountains, or even schools as Whites (and more). Interestingly - related to the above point of peoples’ “becoming” White over time - interracial marriage between Whites and Blacks resulted in new nonwhite ethnic categories for their children. Mulattos had half-Black ancestry, Quadroons had quarter-, and Octaroons had eighth-Black ancestry. You see photographs of these people and you think that person is “white-passing” but legally these people where technically not White and experienced a different, but similar, treatment as Blacks and other nonwhites.
White-passing is a complicated and important concept to digest. Often it means someone might be entitled to the social privileges associated with Whiteness, and remember - it means that their physical characteristics “look” “White” - again, in my argument, a made-up racial category based on centuries of intermixing from different places.
A tangent - I wish I had some more education on Germany’s concepts of Aryan supremacy (blonde, blue eyed folks) because they were happening at the same time as some of these categories were being amalgamated into White in the American censuses (1920s, 30s, 40s). I think it’s an interesting take on what goes wrong in racial categorization - what were Germans with brown hair and brown eyes “passing” as?
Back to white-passing because it’s close to the spirit of your question. What are these Brazilians doing on the whitepeoplegifs subreddit? Race has become an easy thing to “simplify” nowadays on the globalized internet but for the historic origins it’s wildly complex, and has become a global topic faster than historians or ethnographers can keep up. And the reason this topic is very American-centralized is because.....those other colonizers weren’t using a census, for instance, Spanish colonies didn’t do this, and so the very concept of being Hispanic or Latino or White is currently up for debate in the USA. Literally for the 2020 census there were specific questions about if you might identify as “White, non-Hispanic” or “White, Hispanic or Latino.”
Now for my emphasis on NOT being from Brazil so NOT being exposed, at all, to the historic timeline of race categorization there. But Portuguese colonies aren’t Spanish colonies so they fall into the “Latino” category (vs “Hispanic” which generally also falls into the Latino category if the country in question is in Latin America). Latinos, having ancestry hailing from Europe, are often white-passing, they look white, or at least they pass as white to people on the internet - so they get posted to whitepeoplegifs.
At the end of the day, NOWADAYS I’d argue, being white-passing or white is not about what country you came from, what country you live in, what your actual genealogy is, it’s about what makes you seen as white. And it also IS about all of those other things. And that’s why this topic can be really confusing. It’s because it’s a made-up category by the government for sorting people and distributing resources.
White supremacists HATE him for this one simple historical trick! IT’S ALL MADE UP!