The idea of a fair where a bunch of different kinds of human vanities are for sale comes from John Bunyan's Christian allegory Pilgrim's Progress. (We'll pause a sec here while you check out the "What's Up with the Title?" section to catch up on that. Back? OK, moving on.)
Thackeray plays it up to the hilt. In Vanity Fair, social life – especially the hierarchical, snobby, get-ahead version of society that Becky is forever trying to conquer – revolves mainly around trying to figure out exactly what each person's particular vanity is, then giving them enough rope to hang themselves with it. Check out how Becky wins over Pitt by fixating on his diplomatic and political skills and never letting up her constant praise. Or look at how Pitt figures out that the key to disposing of James Crawley is to work on his frat-boy swagger. Conversely, we can see that James Crawley fails to secure Miss Crawley's affections (and inheritance) because he doesn't understand that, although she talks a big game of being liberal and democratic, she is actually extremely conscious of and vain about her high birth and noble station.
Those who know how to read and take advantage of the self-deceptions of others in Vanity Fair tend to do well. Those who don't fail. And every now and again the narrator will step in and bemoan the shallowness of vanity.
The piano, besides being a tangible object and plot point, is a symbol in the book. Bankruptcy forces the Sedleys to auction off all their things, including this little piano. Dobbin buys it and sends it back to Amelia. She thinks it's a present from George and it becomes her favorite thing ever. When she finally realizes that Dobbin bought back the piano, she immediately declares that "It was valueless now [...] it was shockingly out of tune" (59.30).
The symbolism isn't hard to tease out, right? The piano is a neat stand-in for Amelia's feelings for the two men and their feelings for her. She is deluded enough to think that George would buy it for her; selfish George would never think of doing such a thing; and Dobbin is so meek and pathetic that not only does he buy her the piano, he doesn't even correct her when she thinks George bought it. Seriously, get a spine, dude.
Another relatively easy symbol to figure out. Amelia has a little portrait of George hanging in her room. Every time she so much as thinks about moving on after his death, she gazes at this picture and it commands her to keep loving him and him alone. Now think about what kind of wall decorations people often use to guide them in making life decisions. Things with some religious significance, right? We'll throw out the idea that Amelia has replaced whatever belief system she had with her idealized, false, misguided love of George. He has now become an icon for her, or even an idol (you know, the bad kind that thou shalt not worship according to one of the ten commandments). Which is always bad news.
Becky's Many Costumes
Becky puts on many different costumes throughout the course of the novel. Some are completely literal, like the sexy toga she busts out for her star-making turn in Lord Steyne's charade. There's a lot going on in that scene. First, Becky is revealed to be an amazing actress, which is great for the stage but not so much for honest, real-world relationships. Second, she makes for a really convincing Clytemnestra, a woman who murdered her husband, which doesn't bode well for Rawdon or, later, Jos. And third, this triumph is the beginning of the end for her, since the thing that gets her to the top of the social heap – her appeal to men – is the thing that will be her downfall.
Some costumes are metaphorical, like when the narrator describes Becky as a siren: the part above the water is beautiful and can sing amazingly, but there's a horrible cannibalistic monster underneath. Clearly Becky doesn't literally eat people, but she does use her considerable charms (a.k.a. hotness) to lure men to her, extract as much from them as she can, then casually toss them aside. This comparison is also a way to point a finger at the audience. After all, we've been sitting there the whole time totally on Team Becky, not giving a second thought to how thoroughly immoral she actually is.
And some costumes are part literal, part metaphorical. For instance, the white dresses Becky wears on her honeymoon. White equals virginal and pure. And Becky? Not so much. But that's what the world expects to see, so that's what she wears. Or take the little white shirt she pulls out of her sewing box and works on every time she needs to look all feminine and maternal – a little shirt that the narrator tells us has been way too small for Rawdon Jr. for quite some time. She uses it most when helping Pitt with his Parliamentary career, which makes sense, because back in the day, women weren't supposed to be involved with men-only things like politics. What better way to be all "I'm just a little housewife listening to you talk about things I don't really understand" than to do some embroidery.
5,000 Pounds Per Year
Sometimes even Becky feels kind of guilty about her doings. When she does, she rationalizes:
"I think I could be a good woman if I had five thousand a year. I could dawdle about in the nursery and [...] and order half-a-crown's worth of soup for the poor. I shouldn't miss it much, out of five thousand a year [...] I could pay everybody, if I had but the money." The narrator is right there with her: "And who knows but Rebecca was right in her speculations--and that it was only a question of money and fortune which made the difference between her and an honest woman?" (41.38)
So what's the big deal about Becky's little fantasy? It points to one of the novel's big questions: do we do what we do because of our circumstances or because of our character? What do you think – could Becky be a good person if she had been born with a lot of money and didn't have to worry about supporting herself? What if she had suddenly inherited it as a young woman (say from Miss Crawley)? How would she be different? Or would she?
Napoleon is obviously a real guy, but he's important to the novel because he hugely influences the plot without ever showing up in the world of Becky, Amelia, Rawdon, and George. We'd like to suggest that he's a kind of double symbol.
On the one hand, we have Becky-as-Napoleon. Napoleon works as a kind of emblem of limitless, relentless, inevitable conquest. Becky is often compared to "the Corsican upstart" (Napoleon) and Thackeray frequently describes her actions in military terms. She is always invading or attacking or routing the person she's dealing with. What do we make of this comparison? Is Becky really the Napoleon of her social world?
On the other hand, we've got Napoleon-as-fate. Think about how wide-reaching the effects of his escape from Elba and return to the battlefield are on the people in the novel. Of course his return summons George and Rawdon to fight in Brussels, but even before that it upsets the financial markets Mr. Sedley depends on, thus wrecking his relationship with Mr. Osborne and affecting Amelia's marriage.
Thackeray spends a paragraph teasing out this chaos theory idea, the notion that a butterfly flapping its wings could cause a tsunami a thousand miles away. In this case, it's the reverse:
[…] is it not hard that the fateful rush of the great Imperial struggle can't take place without affecting a poor little harmless girl of eighteen [...] Yes; Napoleon is flinging his last stake, and poor little Emmy Sedley's happiness forms, somehow, part of it. (18.2)