From the back of the book (UK edition):

Style guru Sara B. has had the job — and joy — for the past fifteen years of eviscerating fashion victims in her legendary DOs and DON’Ts magazine feature. But now on the edge of forty, with ambitious hipster kids reinventing the style world, Sara’s being spat out like an old Polaroid picture.

Fuelled by alcohol, nicotine and self-loathing, Sara launches into a cringeworthy series of blowups — personal, professional and private. She seems bent on destroying everything she’s worked for. Can the faltering fashionista find her way back to the cutting edge?