On the BusYou can save yourself a trip to Ocean Park for an amusement ride by sitting in the in the very front seat upstairs in one of Hong Kong's double-decker buses.
If you sit on the right-hand side, you'll notice a small rectangular porthole. Glance down it quickly and you'll see the driver's head. He can look up through this window to the angled mirror in the ceiling to make sure everyone is behaving on the top deck.
I took this self-portrait in the overhead mirror.