I appreciate the use of imagery, but the key to using it as a literary device is subtlety. In this book, imagery doesn't gently tap you on the shoulders from behind, it doesn't touch you with a gentle lover's caress. The imagery within this book comes running at you in a Pennywise mask wielding a chainsaw while screaming bloody murder. The writing is overwrought, leaning heavily towards purple prose. It tries too hard to be "gothic." It has all the subtlety of a purple plaid-patterned penguin. 
 You could play a drinking game while reading this book. Take two imagery. Bells. Birds. You could take a sip---not a shot, mind you, just a sip---of a low alcohol-by-volume wine with every instance of those imageries and still end up dead by alcohol poisoning before you reach the 50% mark of this book. 
 There is an emphasis on collective nouns in this book, because it's one of the things a girl entering Blythewood must know. You have to know terms like a teal of magpies. A murder of crows. An exaltation of larks. A cete of badgers. I would like to take this opportunity to create my own collective noun to describe the writing in this book: a fuckload of frivolity. 
 (Yes, I deliberately used some terribly imagery and alliteration myself in describing the terribleness of this book. It's fine, I'm not an author, and the readers of this review are only subject to my atrocious writing for the length of an overly verbose review, not for all 400-something freaking pages of a book.) 
 This is one of those times when I reflect back to 11th grade AP English Literature and mentally shake my fist at my old teacher. Thanks to that damned class, I can pick out and analyze every single terrible use of metaphor, imagery, symbolism in this book. This book wasn't terrible, but it was generic. The characters are recycled, the romance is chock full of tropes (and comes complete with insta-love and a love triangle), the atmosphere and paranormal premise is interesting, but it doesn't make up for the fact that I cannot get over the writing. This is, of course, my opinion. I understand perfectly if some people reading this book find the writing beautiful, evocative. Not me. Again, I blame the many analytical essays I had to write in high school for my aggravating reading experience. 
 Summary: Avaline Hall is a seamstress at the Triangle Shirtwaist Factory in 1911 New York. That is a bad thing, and a real thing that actually happened. I won't go into the details because it is largely irrelevant to the story, but in short, nearly 150 people died, and Avaline was almost one of them, but she was one of the lucky ones who were rescued. It is a tragedy, yes, but in the middle of a fire, I would be screaming my ass off and running around like a chicken with its neck cut off (and probably die a horrible, fiery death), but I sure as fucking hell would not be having thoughts along these lines, looking at girls who are jumping out of a building to their deaths because there is literally no other way of escape. 
 "I thought the same thing," I said softly, my voice quavering, "when I saw the girls jumping...that they were like butterflies trapped between panes of glass." 
 Get your head on straight. 
 Avaline's backstory is kind of a mess. Within the first 5% of the book, we learn a multitude of things about Avaline that makes her just about the most unrealistic heroine ever, even for an YA PNR. We learn that she's the daughter of a woman who was formerly wealthy but who ran away from home and works as a hat trimmer instead. 
 Contrary to popular beliefs, the most dangerous occupation isn't that of a bomb squad technician, a soldier, a police officer, a firemen. Nope. The most dangerous occupation in the world is being the mother (or a close blood relative) of an YA heroine. Her mother commits suicide due to laudanum poisoning, and Avaline is forced to work for her own support. She ends up at the Factory as a curiously incompetent seamstress, despite her skills at making hats. She keeps hearing weird bells inside her head that warns her of imminent danger. She keeps seeing the same strange man in an Inverness cape everywhere. She falls into insta-love with some idiot boy (who is *GASP* not who he seems!!1!1!) shortly before the fire occurs. 
 My whole body shuddered like a bell that had been struck. My hand, which looked small in his, was trembling. For a moment the din of the factory--the whirr of the sewing machines, the shouts of the foreman to hurry up, the street noise from the open windows--all receded. I felt as though the two of us were standing alone in a green glade starred with wildflowers, the only sound the wind soughing through the encircling forest... 
 After being involved in the fire, Ava rants and raves like a lunatic because a weird boy with wings rescued her, and surprise, surprise, is actually committed to a mental hospital for 5 months. She is then rescued by her grandmother, and sent on an interview to Blythewood. Blythewood is the very prestigious girl's finishing school that her mother attended before her disgrace. Ava has harbored hopes of attending it, due to her mother's stories, and true to the tradition of cutting off your nose to spite your face, Ava acts like an absolute contrary bitch when she actually gets the chance to attend the school of her dreams. Wah wah wah. Boo fucking hoo. No, I don't want to attend a private school where my mother and I have always wanted me to attend. No, I don't want the protection of my wealthy grandmother. I just want to be a seamstress again so I can toil away my life without prospects. Shut the fuck up and enjoy your good fortune. 
 Blythewood is...weird. Really, really weird. The interview itself was freaky enough, the people are strange, and curiously, nobody questions anything until they're confronted with the truth of the place. There is one eligible boy in residence. One. Boy. In an all-girls' school. Nathan is the bad boy. Enter the love triangle. Nathan is an asshat, a spoiled, carefree boy who scrapes along in life due to his money, good looks, and influential family. 
 Naturally, in a school full of accomplished girls, beautiful girls, wealthy girls, Nathan would totally go for the one girl who's so *sigh* special. Yep. Avaline. 
 The romance is dumb. The love interests are cliched. The mysterious, ethereal boy is as generic as they come. He's apparently ebony and ivory. A marbled, chiseled Adonis... 
 ...he possessed the finely carved features of a Greek statue, his skin pale as marble, his eyes the weathered gray of worn granite. And a heart as hard as stone... 
 with wings so black you'd have to actually look close to see that his wings are actually all the colors of the fucking rainbow. 
 Those wings weren't entirely black--they held the iridescent colors of the sunset in them. 
 WHAT THE FUCK? He's dangerous. The boy's name is Raven. He is a Darkling, but don't be fooled, this ain't Shadow and Bone's Darkling. There is no complexity here, and there is no questionable line of good versus evil. There's just a line between dullness and boredom. This book's Darkling doesn't hold a candle to the original. 
 The characters are generic as all gets out. I don't have anything to say about Ava because she puts me to sleep more effectively than an overdose of Lunesta. The other characters in the book are cookie cutter. The silly, frivolous, but kind-hearted rich girl, Helen. The eager-to-please, naive, bumbling small-town girl, Daisy (from Kansas City, Kansas). Sarah, the intelligent, competent, poor scholarship girl who hates the status quo and is eager to prove herself. The bitchy "mean girls," clique of George, Fred, and Wallie (all girls, who are nicknamed after their enormously wealthy fathers). The fat, incompetent, bitchtastic Etiquette mistress. The ice-cold, butter-wouldn't-melt-in-her-mouth headmistress. 
 The names are Dickensian, in that the characters' name are a reflection of their work, of their character. Cute, but if I wanted Dickens, I'D READ DICKENS. Matilda Swift, the bow mistress. Euphorbia Frost, the bitchy etiquette instructor. The kind, motherly cluck of a secretary, Miss Moorhen. Martin Peale, the Bell Master. Mrs. Calendar, the Latin teacher. Vionetta Sharp, with her violet eyes and violet-growing spinster aunts. Enough is enough. 
 As I said. The characters are generic, through and through. The plot is decent, the use of the bells is unique, and the mystery---well, let's just say at least there are no vampires or werewolves. You can throw just about every single otherworldly creature into the mix, though. This was a really, really long book, and it got pretty boring before the pacing picked up. 
 The worst part about this book was the writing. I just could not overlook all the terrible use of imagery, strange and stupid metaphors, and tendency towards purple prose. Allow me to present some examples. 
 "It was like striking a match to kindling. What had seemed cold was now warm--or perhaps the warmth had been kindled in me at the thought that he'd lit up at the sight of me." 
 "It spread like cracks in an old China teacup when you pour hot water into it, only these cracks were made of fire and burned away flesh, changing him before my eyes from the beautiful boy of my dreams into a horrid monster." 
 "So that's where he goes, I thought...he has a forest inside him." 
 A blond head is a "golden waterfall, an "angel's halo". 
 And the bells. THE BIRDS. SO MUCH BIRD IMAGERY. I feel like I'm in a Hitchcock film. 
 Here are a couple of examples. Or 10. 
 "The names fluttered through the air like brightly colored birds." 
 "You look as comfortable as an eaglet in its cliff-side aerie." 
 "She said something and Miss Sharp tossed her head back and laughed, the sound like the nightingale's song." 
 "In the firelight her pale gray eyes shone yellow, like the eyes of an owl sweeping the forest floor for prey." 
 "...she moved around the room like a trapped bird in a cage." 
 "He had taken himself off to a window seat overlooking the river and made a nest of books like a peregrine on a cliff." 
 "I've seen you hunched over them like a hawk mantling its prey." 
 "I noticed how small my hands looked in his, like doves cupped in a nest. They fluttered like doves, too..." 
 "Cam, her hair sticking up in spikes, looked like a newly hatched chick eager for her first flight." 
 "...setting Miss Corey fluttering over the books like a mother hen gathering her chicks under her wing." 
 "He lifted his head away from Miss Frost's ear and swiveled his neck like Blodeuwedd when she heard a mouse squeak--only his eyes were colder than any owl's." 
 "And pale," Miss Fisk added, tilting her head at me like a robin listening for worms in the ground. 
 "Gillie scowled, his dark eyebrows swooping together like two hawks fighting over a morsel." 
 ...you get the point. 
 I believe you would be better off reading Libba Bray. It may be cliched, but at least the writing doesn't stand out for the worse.