Gamand explains this further on her website:
The flower crowns are an invitation for the viewer to look at pit bulls with a new eye. Hundreds of thousands of pit bull-type dogs languish in shelters around the world, because of our prejudice. Most of them end up euthanized. Their owners get evicted or have difficulties finding apartments. Some cities or countries ban them, which leads to terrible consequences. Because of our prejudice, pit bulls have been marginalized, making them the most neglected and abused dogs. The shelter pit bulls I meet are great companions who wouldn’t hurt a fly. They deserve better.