What does "facing 305° NW" mean on the spot pages?

Not obvious at all, and it is the single most useful number on the page once it clicks. It is where you point the camera, not where you walk. Stand on the pin, face 305° on your phone compass, and that is the frame. The text after it tells you what you should be looking at when you are facing correctly — so if you are at Marina Barrage facing 305° and you cannot see the CBD skyline over the water, you are standing in the wrong place.

That makes complete sense now, and it explains why I could never find the shot at Henderson Waves. I was on the right bridge facing the wrong way the whole time.