These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
"She had seen enough of her pride, her meanness, and her determined prejudice against herself..."
From chapter 8:
"A woman of seven-and-twenty," said Marianne, after pausing a moment, "can never hope to feel or inspire affection again...
Strangled by the Red String: The novel never really explains why Edward and Elinor fell in love, focusing much more on Marianne's romantic relationships. Emma Thompson went out of her way to rectify this in the film, to the point where many fans consider the film superior, at least in this regard; the 2008 miniseries takes its cue from Thompson's screenplay, and is much the better for it.
Values Dissonance: Edward's persisting in the engagement is portrayed as the honorable thing to do. However, the modern reader can't help noticing that Edward's stance would lead him to a life-bonding contract with an individual he no longer cared about. The engagement is also technically void (made by two minors without their parents' consent), meaning it's not legally binding; Edward sticks to it because he feels morally bound. As one fanfiction writer puts it, "I made a promise I was a teenager, and it is only honourable that I be bound by this promise for all eternity". With that said, Edward's breaking off the engagement would have absolutely ruined Lucy's reputation forever and destroyed her chance of ever marrying, let alone marrying well. Given her financial situation, that would be a sentence to ruin. Only women in the Regency era could break off an engagement, and even then it was a risk; Lucy only got away with it because she married Robert immediately thereafter.
Wangst: Deliberate — Marianne's response to her romantic woes begins to take on this edge, which to her credit she eventually comes to realize.
Their mother is Madam Pomfrey, and the nice old lady who takes them to London is the (original) Fat Lady from Gryffindor Tower, who lives with Cornelius Fudge. The Harry Potter movie sets were practically a reunion party for the cast of this film.
Watch Imelda Staunton (Mrs. Palmer) interact with Emma Thompson in this film, then follow it by watching their characters interact in Harry Potter and the Order of the Phoenix. You might never look at Dolores Umbridge and Sybil Trelawney the same.
Hugh Grant and Emma Thompson play siblings in Love Actually. Emma Thompson is also married to Alan Rickman in the same movie.
Hugh Laurie playing sarcastic Mr. Palmer years before House. And stealing the show.
Tear Jerker: Elinor's desperate speech to Marianne when Marianne learns that Edward has been engaged to Lucy Steele. From someone normally so reserved, it's absolutely shattering.
Elinor: Believe me, Marianne, had I not been bound to silence I could have produced proof enough of a broken heart even for you!
This troper cannot sit through Edward's speech to Elinor at the end ("my heart is and always will be yours") without crying.
Values Dissonance: In the movie, Colonel Brandon was forbidden from marrying his cousin Elizabeth because she had no money. In the book, she was forced to marry his brother specifically because she did have money - and it had to stay with the oldest son to keep it in the family.