Client establishes a tcpcrypt session with what it thinks is Real Web Server but is actually Evil Middlebox replaying the request to the server and the response back to the client.
Yeah, I'm not sure what the parent was getting at separating them out since from the clients perspective they're the same. I guess they mean that getting a tcpcrypt connection on your server isn't a guarantee that there isn't a middlebox either.
Client establishes a tcpcrypt session with what it thinks is Real Web Server but is actually Evil Middlebox replaying the request to the server and the response back to the client.