To calm you down until someone comes along with pics, I'd say they will find some way to make use of the existing wiring. I'm in an apartment complex with all the fiber run to a common location. They then used the existing copper wiring to connect each unit. That's called a VDSL2-style connection and it requires a DSL modem (I know it sounds ugly, but I still get my full speed) and then the standard FiOS router. The tech wired up the jack nearest my computer as if the jack was going to connect to line 2, and plugged the DSL modem into that.
When the tech arrives, I'd point out your "demarc" point and let him figure out what to do.