I would’ve found it similarly both racist and harmlessly humorous if the author was going to a party and said “I channeled my inner Jamaican and tried to dance.”
Or if she was going to the interview and said “I channeled my inner German and got there exactly on time.”
Like, it’s fine. Good-humoured stereotyping is fine. Self deprecation is fine. We don’t all have to be passive aggressive all the time just waiting for people to screw up so we can dunk on them.
The flagged comment was saying something negative about a group.
The original article was self deprecation (they don’t ask for enough) and complementary about the group it stereotypes (sticking up for oneself).
With being white it’s not so clear here. Being white doesn’t definitionally come with clear net privilege because it’s such a diverse group: your life is likely much better than some devestatingly poor white person in Appalachia, or even just the majority of white people if you work in tech.
As a test for privilege, ask yourself: “would I trade places with a random white person and accept these racist comments”? Is that a “good deal” like with the rich person example? It’s not clear and probably not worth the risk you end up trading places with the many white people in crappier circumstances than you. That’s exactly the proof: many many white people don’t have so much privilege that you’d happily trade places and take all the racist comments too. In other words: it’s really NOT punching up in many many of the circumstances, many of the white readers who see your comment, it is just exactly punching down for them.
Not that the above should even have to be argued, being racist isn’t ok even if it’s punching up, just as sexism against rich women isn’t ok, or homophobia targeting rich gay men. Jewish people are exceedingly successful as a group along dimensions like income and wealth, so it’d be “punching up” in some sense, but does that justify antisemetism? Of course not. Trying to justify racism with “it’s punching up” just comes across as “I want to be racist but don’t want to be seen as a racist”.
We’re smart enough to convey our viewpoints without having to insult. It only helps with our righteous self-indignation at the expense of making inroads towards actual, positive change.
Here's a heuristic I've found useful -- if you replace the race, age, or sex signifier and it ends up sounding racist, ageist, or sexist, turns out that your original statement is in fact also racist, ageist, or sexist. Frustrating inclusion in an otherwise interesting article.