192.168.x.y are considered reserved for private networks and not for the internet at large. So your work (and home) routers are assigning that address to your computer for those networks. The external-facing connection, though, has two addresses--one for the outside, and one for the inside (192.168.x.y). The outside-facing connection is the one being reported by whatismyipaddress.com.
Thank you very much..I thought You didn;t answer because the question was beneath you LOL.
BTW, I asked my co-worker who also brings his laptop (a Macbook Pro) and his address while at work (same as mine) is 192.168.1.10, which is close to mine. We were both stumped. We asked our arrogant “IT” guy and he dodged the question.