So, more yeses than noes! Here we go:
The sentence is 12 words long, two words of which are French loan words. French loan words are not pretentious by themselves, but I think we can and will start building a case that they're pretentious af here.
Our first loan word drew a lot of heat for being somehow both rare/unknown and also misused, because "everyone" knows that's not what silhouette (sil-oh-WHET, btw, if anyone was in the same boat as the TikTok vics;) means.
Except it sort of, a little bit is. A silhouette is most commonly understood as a dark outline against a bright light. In fashion, the outline of your look is not the be-all, end-all of design, but it's a big consideration, especially when you get to the little turn on the catwalk level.
In fairly niche discussions of fashion design, it wouldn't be too weird to refer to a model's outfit as their "silhouette." Not especially common, a little awkward here, definitely reaching for sophistication that might not be there, but it could happen.
Then, her silhouette of clothes burst forth into extraordinary, the next word some of the ambushed high schoolers had trouble with. All those syllables! WTF!! Why is this here!!!
Because if her silhouette isn't wowing you, dear reader, let's elevate this b¡tch and her look into the stratosphere with a multisyllabic word bomb straight from the PSAT! Flash! Pow! Fancy! Are you not enter- I mean, impressed?
No? The let's do some of that fancy writing sh¡t and go understated with "somewhat"! That's all learnéd and stuff, right? I'm telling you it's sophisticated, so suddenly stepping down the tone must be.
You're still looking at me funny, so it's time to drag the vowel-crazy Frenach back into this and lob another loan wordbomb with gauche (hard g-long oh-shh, extra silent e because French c'est sexy!) to round out the twelve words of tortured prose, just to make it sophisticated.
OK, maybe a little awkward. Possibly even inept. But that TikTokker definitely swung for the fences of sophistication.
Now, go look up the word "gauche" and tell me you're not looking at a 12-word pun.
Or, I can just tell you that Merriam-Webster defines "gauche" as socially inept, with "awkward" and "tacky" as synonyms, and point out that I've only read and heard it used to denigrate people who were trying to appear wealthier or more sophisticated t han they were and failing badly.