These images are of pollinaria, the strange and wonderful fertilization saddlebags of the milkweed, among other flowering plants.
A pollinating insect, a monarch butterfly for example, stands atop the milkweed flowerhead. Usually there would be a layer of pollen dust waiting to catch a ride, but in this case, a wee pollinarium detaches from the flower and hooks itself to the leg or mouth or antenna of the insect to be transported to another milkweed, where it then detaches itself.
Milkweed plants are the main food source for monarch butterflies. Once common, milkweed has been eradicated across large areas of its former native habitat, mostly due to farming and pesticides.
There’s a detailed description of how it all works here, but mainly, I like that the plant pollination structure looks like a paddle-legged insect itself.