If you really want to know: Go take a look at what things they think interest you. Go to Settings, Privacy and Safety, Content You See, Interests. You'll find they've probably randomly inserted some interest in there because you engaged with someone who had that interest and it never ever gets turned off. I followed an actor because I liked his stance on some topic or another and it decided I must be interested in his latest project... which I'm not... and no matter how many times I uncheck that interest it will just get set again within a week or so.
So, yeah, they try to make inferences about what you'll like based on who you interact with, they invariably prove to be wrong, and here we are. I suppose they may also be paid to astroturf interests to other people, but who knows?