The speaker is driving past a house trailer at the bottom of a pasture, and one of its long walls has been removed. Anyone speeding by on the highway can see straight inside: a tiny kitchen, a living room with a sagging sofa-bed, two bedrooms, a closet standing empty. The comparison to a Japanese bento box is oddly neat and almost cheerful, as if the home were a meal laid out for passersby.
The poem turns in its last lines. The speaker imagines the people who lived there, "white as rice," growing "round on next to nothing" and never feeling full. The food image now suggests poverty and a hunger that was never satisfied, not just a clever comparison. The mood is quiet and a little uneasy. The speaker's glance from a car with the sunroof down and the radio blaring feels casual, even careless, while the bare rooms hold a sadness the speaker can only guess at. The poem makes us notice how easily we look at other people's lives and keep driving.