Why does the narrator mention feathers? in a servant to servants

to emphasize how free the camper is to do as he pleases

The narrator mentions the feathers to imply that the camper is engaged in a trivial activity

Explanation:

In "A Servant to Servants" by Robert Frost, the narrator is a woman who suffers of mental illness and loneliness even though she has people around and she talks about this camper that is out on the fields in her husband's land and how he let himself go with banal things since it seems there's no much more there

Those lines are:

Our Willoughby! How did you hear of it?

I expect, though, everyone's heard of it.

In a book about ferns? Listen to that!

You let things more like feathers regulate

Your going and coming. And you like it here?

not sure how to answer your question sorry