The original example, of a single house with the global address of
"The Tulip, UK" is a naturally occurring example of something like ARP
or something like tunneling, not something like NAT. The distinction
is betweeen doing a mapping/encapsulation and doing an address
substitution. NATs are all about doing address substitution; the
post office does mapping/encapsulation to deliver to The Tulip.
Number portability is probably a better example - in the
US, at least, the called party's address is swapped out
at the ingress "router" and then swapped back in at the
last hope "router."
Melinda