You probably notice that compared to imagining the water drop and the leaf in isolation, the juxtaposition in this image makes you notice more about each of them.
Somehow, by putting them next to each other, the water drops seem 'droppier'—more round, glossy, smooth, liquid, reflective—than usual, and the leaf seems 'leafier'—more textured, complex, intricate, skin-like, resistant, coordinated, articulated.