The opening imagery of "The Selfish Giant" is essential for setting the mood and establishing that the story belongs to the genre of literary fairytale.
It was a large lovely garden, with soft green grass. Here and there over the grass stood beautiful flowers like stars, and there were twelve peach-trees that in the spring-time broke out into delicate blossoms of pink and pearl, and in the autumn bore rich fruit. The birds sat on the trees and sang so sweetly that the children used to stop their games in order to listen to them.
This opening draws heavily on visual imagery, as the narrator describes the "green grass" and the many flowers, trees, and birds. There's also some tactile imagery at play, as the grass isn't just "green" but also "soft," thus capturing the lush and comfortable nature of this environment. Furthermore, the story gestures toward auditory imagery by mentioning the birds as they sing "sweetly" to the children below. All of this exuberant imagery stands out in relation to Wilde's otherwise concise style and the speaker's otherwise matter-of-fact tone. Although Wilde clearly values narrative simplicity in the story, he balances this with his desire to fill the story with rich imagery.