Sure, I suppose I can make an attempt...
In modern internet culture, it's an overwhelmingly common[^1] practice to mentally classify things with as few labels as possible (ideally just one label), ignoring the possibility of misclassification or nuance.
Applying that practice to the flags in the photo, the meme author likely[^4] mentally classified each flag like this:
- Thin Blue Line flag = Pro-authority
- Gadsden flag = Anti-authority
Because the possibilities of misclassification and nuance are ignored, we can assume that these labels are correct.
Because the labels are correct, we can assume that it is actually the owner of the flags who is confused – not the meme author, nor us beholders/doomscrollers with whom the meme resonates.
Thanks to the logic of our "chain of assumptions"[^2] being correct, we can feel validated because our team wins again, and their team loses again[^3]. We are drawn to this feeling. We are more likely to upvote things that make us feel this.
This sort of mindset is not only socially acceptable, it is strongly encouraged[^1].
Footnotes
[^1]: Example: This post has 640 upvotes and 5 downvotes. (By the way: Those 5 down-voters are alt-right, Trump-supporting, boot-licking, racist, homophobic, transphobic, xenophobic, misogynistic, fascist nazis[^4][^3].)
[^2]: There might be an actual name for this. I'm just making this name up without bothering to research because I assume that most readers won't care.
[^3]: Warning: If you are wondering, "How?": Stop. It is socially unacceptable to ask this. It can only mean that you disagree[^4], and you risk being shunned and classified/labeled accordingly.
[^4]: This is considered correct because the possibilities of misclassification or nuance are safely ignored.[^3]