Here's the interesting part of the article:
"The most popular videos don’t generally offer information about the book’s author, the writing or even the plot, the way a traditional review does. Instead, readers speak plainly about the emotional journey a book will offer."
I think this is one of the key, general principles for marketing in today's Attention Scarcity Age. It transcends the specificity of books and TikTok, and can be applied to any product/service, or platform.
People are overwhelmed and don't need more facts or information. They want an emotional connection, and want to know the payoff from the book.