What does this poem mean? What is th symbolism? Literary devices?

Nothing Stays Put

Amy Clampitt

The strange and wonderful are too much with us. The protea of the antipodes--a great, globed, blazing honeybee of a bloom-- for sale in the supermarket! We are in our decadence, we are not entitled. What have we done to deserve all the produce of the tropics-- this fiery trove, the largesse of it heaped up like cannonballs, these pineapples, bossed and crested, standing like troops at attention, these tiers, these balconies of green, festoons grown sumptuous with stoop labor? The exotic is everywhere, it comes to us before there is a yen or a need for it. The green- grocers, uptown and down, are from South Korea. Orchids, opulence by the pailful, just slightly fatigued by the plane trip from Hawaii, are disposed on the sidewalks; alstroemerias, freesias fattened a bit in translation from overseas; gladioli likewise estranged from their piercing ancestral crimson; as well as, less altered from the original blue cornflower of the roadsides and railway embankments of Europe, these bachelor's buttons. But it isn't the railway embankments their featherweight wheels of cobalt remind me of, it's a row of them among prim colonnades of cosmos, snapdragon, nasturtium, bloodsilk red poppies, in my grandmother's garden: a prairie childhood, the grassland shorn, overlaid with a grid, unsealed, furrowed, harrowed and sown with immigrant grasses, their massive corduroy, their wavering feltings embroidered here and there by the scarlet shoulder patch of cannas on a courthouse lawn, by a love knot, a cross stitch of living matter, sown and tended by women, nurturers everywhere of the strange and wonderful, beneath whose hands what had been alien begins, as it alters, to grow as though it were indigenous. But at this remove what I think of as strange and wonderful, strolling the side streets of Manhattan on an April afternoon, seeing hybrid pear trees in blossom, a tossing, vertiginous colonnade of foam, up above-- is the white petalfall, the warm snowdrift of the indigenous wild plum of my childhood. Nothing stays put. The world is a wheel. All that we know, that we're made of, is motion.

I didn't read all of it but there is the literary device of personification in this piece "these pineapples, bossed and crested, standing like troops at attention,". The pineapples are given the human persona of standing like troops.