I love to show that kind of shit to AI boosters. (In case you're wondering, the numbers were chosen randomly and the answer is incorrect).
They go waaa waaa its not a calculator, and then I can point out that it got the leading 6 digits and the last digit correct, which is a lot better than it did on the "softer" parts of the test.
Pretentious is a fine description of the writing style. Which actual humans fine tune.
Given that the LLMs typically have a system prompt that specifies a particular tone for the output, I think pretentious is an absolutely valid and accurate word to use.
Also, these bots have been deliberately fine-tuned in a way that is supposed to sound human. Sometimes, as a consequence, I find it difficult to describe their answering style without employing vocabulary used to describe human behavior. Also, I strongly suspect that this deliberate "human-like" style is a key reason for the current AI hype. It is why many people appear to excuse the bots' huge shortcomings. It is funny to be accused of being "emotional" when pointing out these patterns as problematic.