Symbolism, Imagery, Allegory
It is important to keep in mind that the gardens we visit in this story are situated in the middle of a bustling urban center. They offer city-dwellers a respite and an escape from the hustle of London life, a return to nature, however temporary. The beauty of the gardens carries them away and has interesting effects on their thoughts. For some, like the married couple, the gardens stir memories of the past; for others, like the young couple, they awaken contemplations of the future; and for the stout lady gazing at the flowers, they create something like a meditative environment in which the rest of the world seems to fade away.
She stood there letting the words fall over her, swaying the top part of her body slowly backwards and forwards, looking at the flowers. (18)
The gardens are a world set slightly apart; they momentarily alter characters' emotional and psychic being. In fact, the vibrant colors, scents, and natural beauty make the gardens seem almost magical at points.
It's also important to remember that the gardens are not naturally occurring, but a constructed, engineered space, meticulously cultivated for the pleasure of the visitors. What's more, the noise and chaos of the city are never far away:
There was no silence; all the time the motor omnibuses were turning their wheels and changing their gear; like a vast nest of Chinese boxes all of wrought steel turning ceaselessly one within another the city murmured. (29)
The gardens might feel like a little paradise (maybe even a return to Eden), but their constructed nature and the noise of city life serve to remind us that the modern, industrial world is never far away. Keeping in mind that the story seems to be set during WW I, this reminder definitely has an ominous tone.