It's using a couple textbook [1] LLM tropes, 'negative parallelism' with a 'here's the kicker' tone.

[1] https://gist.github.com/ossa-ma/f3baa9d25154c33095e22272c631...

But it is specifically one of Claude's ticks

I'm guessing he means overall the kind of circling and concluding that Claude does, like "the actual truth is more interesting than it seems" or "the real smoking gun is not the x, it's the y that was under our noses all this time" type of writing.

This phrasing is a very specific "Hello, this is Claude"