You may have seen this picture. It is a popular choice for people commenting on Twitter about solar.
This project by Conergy is located in New Caledonia, a Pacific island nation 750 miles east of Australia. The September 2014 press release announcing the project has details:
This is a 2 megawatt project with 7,888 solar panels. They explain the reason for the heart shape like this:
The unique design is inspired by the “Coeur de Voh”, or “Heart of Voh”, an area of nearby wild mangrove vegetation that has naturally taken the shape of a heart. The “Coeur de Voh” gained worldwide recognition thanks to the aerial photography of environmental campaigner Yann Arthus-Bertrand in the best-selling book, “The Earth from Above.”
Again, having some meaningful shape for your solar project seems to be an obvious choice. I expect seeing more of these projects in the future.