I looked up knowing a Boeing 787 Dreamliner was somewhere in New Zealand. I even knew earlier in the day @dannews had been fortunate enough to fly to Christchurch in it.
Immediately above a sleek twin engine jet was passing over glinting in the sunset. It's hard to judge the size of an aircraft without reference to the horizon, maybe it was the 787?
Web tech to the rescue as the Flightradar 24 phone app proved this was an Emirates 777-300 at 11,000ft. A very nice aircraft indeed, but not a Dream.