What about Lady Catherine is being mocked? Why is the author mocking it and what does Lady Catherine represent in society?

Lady Catherine is described as "a tall, large woman, with strongly-marked features." Austen paints a vivid portrait of Lady Catherine as an extremely arrogant, egotistical and dictatorial woman. For the entire evening, Lady Catherine does nothing but remind her guests of their inferior rank. And it seems that the only conversation which she tolerates from others is praise of herself or agreement with her opinions. During the dinner she is quite pleased with the exaggerated and continuous praise of Mr. Collins and Sir William. Lady C is exactly the type of gentry Austen, and the character of Elizabeth, would really dislike.

what does Lady Catherine represent in modern society?