I think what's going on here is [a pet peeve of mine](https://music.stackexchange.com/questions/130367/where-do-metrical-accents-come-from#comment242195_130369) as a listener. Once the kick comes in, it's very clear where the beats are. In the preceding measures, the melodic material is just the same, but it's harder to tell where the beats are. The riff plays on beats one and four, but on beats two and three it has a rest on the exact moment of the beat, instead playing a moment later. In rhythmic syllables, if you count "1 e & a," you might say that it plays on the "e" of beats two and three: "ONE E (and a two) E (and a three) E (and a) FOUR E AND A." Or, notated, this: [![enter image description here][1]][1] With no other instruments providing a strong sense of the beat, it's very disorienting on first listen. After all, we don't know that it's notated like this; all we get is bits of sound on a timeline. We wonder whether those isolated C and B are in fact beats, and then are thrown off by the final full set of 16ths. Once the kick comes in, it's not quite where we expect it and it takes a few seconds to calibrate. There isn't a term, per se, for the cognitive dissonance we feel between the unclear (misperceived?) meter of the intro and the clarity of a few bars later, and I can't think of a *good* term for a contrast between a voice with simple rhythm and one with a more complex one. But there might be good terms to describe the guitar part. One *might* use "syncopated," but that could be confusing. Syncopation is often about emphasizing weak beats, or "stretching" simple notes so that they begin early or end late; think ragtime. I think "displacement" might be the most useful word. Google "beat displacement" or "rhythmic displacement" and you find a lot of videos and blogs, like [this one](https://www.elephantdrums.co.uk/blog/creative-concepts/creative-ideas-beat-displacement/), talking about the idea of shifting notes to be ahead of or behind the beat. So it's not a single handy phrase, but maybe the best way to describe this is "The guitar part displaces the notes on the second and third beat, delaying them by a sixteenth note. This creates some metric ambiguity until the kick drum enters, marking each beat directly." [1]: https://i.sstatic.net/yaXQ1.png