I think that is an excellent example of Jane Austen's style of humourous description, whatever its name. How about this one from Ch. 37?

Reflection must be reserved for solitary hours; whenever she was alone, she gave way to it as the greatest relief; and not a day went by without a solitary walk, in which she might indulge in all the delight of unpleasant recollections.

Or that wonderful speech of contradiction and invective delivered by Mrs. Bennet in Ch. 20:

"Ay, there she comes, [...] looking as unconcerned as may be, and caring no more for us than if we were at York, provided she can have her own way. But I tell you what, Miss Lizzy -- if you take it into your head to go on refusing every offer of marriage in this way, you will never get a husband at all -- and I am sure I do not know who is to maintain you when your father is dead. I shall not be able to keep you -- and so I warn you. I have done with you from this very day. I told you in the library, you know, that I should never speak to you again, and you will find me as good as my word. I have no pleasure in talking to undutiful children. Not that I have much pleasure, indeed, in talking to anybody. People who suffer as I do from nervous complaints can have no great inclination for talking. Nobody can tell what I suffer! But it is always so. Those who do not complain are never pitied."