Or by her participating that she is knowingly involving herself in a scam. Which, yeah, it's just books - but it's pretty obviously a pyramid.
No shame if you don't see how it's a scam, the cozy blanket and glass of wine are meant to throw you, and they chose 36 because it's a confusing enough number where you don't think too much about how it grows.
She gives one book to her upline. She then sends out post to 36 more people to give her 36 books. Each one of them then needs to find 36 people each, which is now 1296 people in that level if they each want 36 books. Thus the exponential pyramid. Of course there is zero way each of them will find that many people, let alone the levels below that. It's a scam that benefits those higher up, and the ones lower will likely not receive anything.
Of course she sees nothing wrong with that. She said "Sometimes I get books, sometimes I don't, that's just part of the game". Which... it's not a game when it's real money being passed around.
On top of that, whenever we see a pyramid scheme we should be stamping it out - hard. Folks, please spot the signs and point them out. Don't be afraid to comment on posts calling them out as scams.
Edit: To be clear the idea of a growing book exchange isn't a bad one, as explained in the comments though the way to make it not a scam is to make it 1:1. You either send a book and receive a book, or if they like the 36 number, you change it to "I'll send a book to whoever sends me a book!". Then it's a true book exchange.
I think the only issue is this person not realising if you have 36 people buying 1 book and sending it, 36 people are not getting 36 books. They’re all getting one. Though, it could be a ring where you read then send, so you eventually cycle through to all 36. Issue there is reading speed varies so one person will end up a bottleneck but I mean yeah.
Either way, at this point just make a book club or go get friendly with your local librarian (I mean talk with them you perverts) and they can usually suggest books you would like but may not have chosen for yourself.
Edit: I understand it’s probably supposed to be a pyramid scheme but nowhere is it said in the picture you’re supposed to get other people to send you books and etc, just hey I’ll give you an address to send a book and you’re get a book(or 36).