The cable between the two is the ethernet network that is connected to the internet not a separate ethernet cable between the Hopper and Joey.
Internet connections do NOT need to be made to the Hopper and use bridging, I use a direct internet connection to each Joey and do not use bridging (never have) because when the Hopper was first released there was no such function as bridging each device needed its own connection for the internet so I have always kept it that way.