I think this is a good symbol for global meltdown, as it gives a preview of what will happen, and as it is already very well known. Also, this is a beautiful picture, and this blog is already gloomy enough. I can use a bit of cheerful color.
The design of the Miyajima shrine built on water was chosen in the 12th century because people venerated the island next to it as holy and did not want to desecrate it with a structure, see the Wikipedia article linked above.
People in the 21st century might be forced to build a lot on water for very different reasons. If major cities are flooded, as will certainly happen with the polar ice masses melting down, that is the only alternative to leaving altogether.