To start with, it's not any random story, it's not even only a book series adaption, it's based on the author's real experiences as geek discovered as model. I really love all six book installments, including the three specials, it's my favorite book series.
I only got access to Netflix to watch this adaption. It's here only based on book 1, a book I know by heart. But they also used some ideas and characters from all later installments.
It's definitely aimed for a young audience, reminding me of my favorite teen romance comedy movies, such like Monte Carlo, Never been kissed or Cinderella Story. It's definitely a Cinderella Story, a fashion fairy tale. Harriet's journey to try to make her life better, with some unexpected magic from a "fashion fairy godmother", a beautiful dress, a prince Charming, but still on a journey to discover herself and to love herself. Somehow this adaption feels in comparison to the book like the Disney Cinderella live action remake in comparison to the 1950 animated movie. There's more complexity, more drama, more romance, yet, to be honest, it's definitely not literally the book (I understand some changes, some less...). For fans, there are lovely references and it's so nice that Holly Smale, the original novel author, was co-author of this series, Certainly, the book was not easily to be turned to movie, much with inner reflection, here seen as a kind of voiceover.
Of course, it's a fairy tale and sometimes we all need fairy tales, and so you should have not wrong expectations from the show.
The Netflix series manages to be as hilarious, joyful, positive and manages to illustrate some key ideas, yet, they put a bit too much "Disney magic" and "Cinderella Story" in the "ugly duckling" transformation story, whereas the book series is more private and cozy than dazzling, more bittersweet than saccharine, more edgy than smooth, more thoughtful and quiet than spectacular, more thoughtful and hitting emotionally harder (such like a Maleficent/Scar level villian school bullyAlexa had downgraded to a wicked stepsister vibes Lexie). Such like I also feel with the mentioned Disney live action remake adaption vs original one. Somehow the book series is more quirky, with Harriet being bubbly or sometimes more grumpy etc.. Some ideas can perhaps better to grab as presented here casually on screen...but even if if feels like Einstein hired as elementary school teacher, this is a joyful, feel-good introduction, but of course, not thr full genius.