Speculation and wrong info (Score 1)

There is no Lightning port in the Ethernet port. If you look at the PCB there are however 7 or so connections more than Ethernet needs. To use them, you'd need either a special CAT-5/Ethernet cable with extra or modified wiring, or, possibly, a Lightning cable. Some folks have put Lightning adapters in there from old iPhones to no effect. *It requires soldering to connect a Lightning port, and a spare Lightning port for that matter.* So far all attempts and activating anything have failed. It's more correct to say "there's some bespoke thing going on this the Ethernet adapter on the Apple TV."