The setting of "Having a Coke with You" is pretty specific. Here we are in New York City, home to the Frick collection and many other wonderful museums of art. We even know what time it is. It's 4 o'clock in the afternoon, and we know that that light at this time of day is still "warm." We can then assume this is taking place some time in late spring, summer, or early fall, before that wintry time of the year where 4 p.m. in New York City means icy winds howling down the boulevards as the sun disappears from view.
The warmth of the season is in line with the general tone of this love poem, which is relaxed and peaceful. Our speaker notices the trees (which are, um, breathing), so we can also guess that this poem's conversation is taking place outside. We imagine a serene park bench, or café table, at which our speaker and you are seated, sipping on an icy coke and watching the rest of the city rush by.
In this way, the setting of New York City creates an effective contrast. Usually filled with the hustle and bustle of rampant humanity, this poem takes a break from that rat race. As he steps back from the city—in the same way it steps back from the work of art in general—our speaker gets a sense of perspective. It's not about being part of some grandiose project, for him, it's these small, quiet, private moments (much like the poem itself) that truly give us a sense of life's wonder and meaning.