The poem is a small riddle about an arrow, and about stubbornness, which is what the title "Stubborn" points us toward. The first lines set the scene: an arrow sits in a quiver, and then we see a target that has already been struck, with an arrow stuck in it. The arrow could easily come loose, the speaker says, "with greatest ease," but it simply refuses. The last line gives the reason in a wonderfully plain way: "it likes this spot."
What makes it charming is that the arrow is treated almost like a person who has dug in their heels. Nothing is forcing it to stay; it chooses to. The speaker seems amused rather than annoyed, watching this small act of obstinacy with a shrug. The short lines and tight rhymes (eyes/stuck, ease/spot) give the poem a quick, playful, nursery-rhyme feel. The mood is light and wry, with a hint that stubbornness can be a kind of contentment.