>>3
The way it says "parallel network to the Internet" makes me want to call shenanigans, but it may just be imprecise language.
From what I've gathered, the depictions in the top right and bottom left and simple user's computers as they are on a local WIFI network that is composed of all other users. Apparently, we daisy-chain ourselves and act like intermediary servers for each others' benefit. I believe that is the implication. Some user on the "dark net" should be able to access any given web page that may have been made inaccessible to another user, so a good connection is found via one person or another and is transmitted to the requesting user's browser through other users on the network.
The upper left image is the "parallel network" that we would be creating and I'm not sure how to explain it adequately. I think the former suggestion, though flawed it is, is adequate to suit the purpose it was created for. Maybe this alternate network is merely the control structure for this daisy-chain of personal computers acting as servers for each other.
The bottom is just fluff that crudely simplifies the ISP-Internet-user network as it exists. Crudely.