Can someone be able to me find a theme from the poem "the railway train" by emily dickinson (the poem will be down below) i would really appreciate it

i like to see it lap the miles,
and lick the valleys up,
and stop to feed itself at tanks;
and then, prodigious, step

around a pile of mountains,
and, supercilious, peer
in shanties, by the sides of roads;
and then a quarry pare

to fit its sides, and crawl between,
complaining all the while
in horrid, hooting stanza;
then chase itself down hill

and neigh like boanerges;
then, punctual as a star,
stop--docile and omnipotent--
at its own stable door.