We also learn a major difference between the sisters: Jane doesn't think much of herself, but she sure thinks highly of other people. And Lizzy, of course, is almost the exact opposite.
Jane even claims to have liked Mr. Bingley's sisters.
We then transition to descriptions of Mr. Bingley and Mr. Darcy who are coincidentally very similar to the sisters.
They're both good men, but Mr. Bingley tends to like people and be liked in return, while Mr. Darcy … not so much.
Like, Mr. Bingley claims to have never met a more agreeable, good-looking crowd of women than at the ball, but Mr. Darcy thinks—well, we've already learned what he thinks.
Fine, he'll admit that Jane is pretty. But she smiles too much. (Is that even a thing?)