Regarding the power, your PoE injector is powering the access point, the power is delivered through the Ethernet cable that is plugged into the E410.
Regarding data, the E410 is receiving data via it's mesh link (wireless radio) it then transfers this data through the Ethernet cables to your PoE injector. The Data port of your poe injector then send this data to your Smart TV.
Both Ethernet cables that are plugged into your PoE Injector are transferring data but only one of them is providing power (PoE).
Does that help?