This seems like an ambiguous figure and ground relationship because you can’t tell whether the trees or the buildings are the focus.

 

This ambiguous because the focus is between water and the trees surrounding it.

 

This photo is ambiguous to a certain level because the street light should be the focus but there’s another dominant object nearby . Which are the eclipse in the sky and the tree leaves.

 

 

This shows an obvious figure- ground relationship as you can easily pin point out that the tree in a piano is the figure.

This is is an obvious figure ground relate. because the structure is the focus.

 

This is is an obvious figure ground relate. because the lit matches are the focus.