The "Little Red Book" is the name of Mao Zedong's propaganda book. It's an example of indoctrination.

Marshall McLuhan introduced the idea that the "medium is the message," which is heavily alluded to in this book with images of the printing press, etc. The idea is that changes in how information is shared play a bigger role than the actual content of the messages being exchanged. Chris Cox, the Chief Product Officer, used to regularly talk about McLuhan.

McLuhan also envisioned trends in the change of information media culminating in a "global village," which Facebook echoes here in its mission of "making the world more open and connected." McLuhan expected that this would divide us more than it would unite us.

So I think what the person you're replying to was saying Facebook's appropriation of Mao Zedong and Marshall McLuhan is... weird. Facebook is directly drawing from dictators' propaganda and a philosopher who predicted what Facebook would bring about, and didn't think it was a good thing.