The poem is only four lines long, but it turns sharply at the end. The speaker looks at an abandoned pasture and imagines it given over to cranes, wild birds, rather than to cattle. The cattle are called "that ugliest beast," and then "the soldier-like herd," as if they moved in rows and followed orders. The speaker clearly prefers the open, unmanaged life of the birds.
Then comes the surprise: "whose face I have." The speaker admits to sharing the face of the herd. That makes the dislike feel less like a simple judgment and more like discomfort with himself. He seems to see something of the crowd, the obedient and ordinary, in his own features.
The mood is quiet and a little wry. There is longing for wildness in the first line, and an uneasy self-recognition in the last. The poem stops mid-thought, which leaves that unease hanging.