It looks like there is an egg in the nest, but it's the knob of the black metal arbor that the nest is firmly built around. It's poking up through the bottom of the nest and has oxidized a bit.
In summer the nest was hidden by the foliage of the kiwi vine growing up over the arbor. As I came and went through the arbor gate all summer long, I never knew there was a family just inches away, well hidden in their home fastened to the metal prongs.
Now in November the leaves are off the kiwi and I can see the substantial construction of this nest and how firmly it is attached to the arbor. It was apparently a good home and a sound one.