It's not saying just some, it refers to change in nature or shape in general as methods of increasing ninjutsu power.
But how do you think it does that? It's obviously by the properties of lightning, which can apply to a Rasengan too, making its chakra sharper.
But it's quite literally just adding wind nature to a Rasengan, it's the most basic change in shape + nature transformation you can think of.
But the differences and the increase in power are mutually inclusive. If we know via statements and feats that adding change in nature increases ninjutsu power, and we also know that it can cause unique properties, it just makes more sense that they stack in this case. Also, I argued against this before as I didn't think it was concrete enough, but the fact that Delta survived a Rasengan of similar size (yes I'm aware it wasn't SPSM Naruto's full power, just comparing it to Base Naruto's) does lend some credence to Boruto's being amped to completely obliterate Momoshiki, who while weaker, could withstand SPSM Naruto's blows.