The leafy tree canopy adds a sense of intimacy. The curved stone path is edged by soft shade plants and annuals — proving that you really need only a few feet of space to make a garden. And the copper birdbath placed at the foot of a mature shade tree is an inspired addition.
Love the idea of growing herbs/plants between stepping stones as the ground landscaping. If you have to retain a tree growing out of the middle of your patio - make a feature of it as they've done here by edging it with box topiary.