The poem begins with something almost invisible: a person reading. The eye moves slowly, the heart keeps a steady beat, and the mind quietly flinches with pleasure, a delight so faint and so deep that the speaker compares it to something felt before birth. Then the view shifts to the street below, which the speaker describes in deliberately flat, almost comic terms: sidewalk, street, sidewalk, all "inelastic matter." Yet the buildings are full of "homegrown beings," and some of them are reading too.
That small detail connects everything. The speaker sees people as collections of "silly and loveable cells," all sharing the same bliss that sustains them and is sustained by them. The tone is warm, playful and a little awed. The closing line, "(now turn the page)," pulls us back to our own reading, so we become one of those readers, linked to the street by the same quiet act.