Under location, I usually see valid IP addresses, but often I see local addresses (192.168.x.x). How does one display a local network address instead of the Internet-visible address?

The internet is a tricky place especially when it is impossible for a machine on the LAN to know its external (WAN) address without using a remote host. The internet is also a scary place especially when you are in an 'untrusted p2p zone' network where anyone person can lie to you at any time.