Good eyes, Paul! [humble bow]
The phone POP box has a protection means in it (IIRC), and has 2 covers. The owner/occupant can open one side, the telco the other.
Inside are two RJ11 (4 conductor) phone plug jumpers that can be removed to perform line troubleshooting, as well as screw terminals that the inside-the-house feed line connects to. This design also allows a POP to serve as a junction point for several lines (up to four) for each building / residence.
