The speaker starts out puzzled. Tree bark is rough, broken and torn, and to their eyes it isn't beautiful at all. So why do cats purr against it, and why do people run their fingers along it with curiosity and wonder instead of disgust? The speaker admits they can't see what these others see.
Then the poem shifts. The bark is described almost like a person who has "gone through hell": old, battered, not smooth. Yet when it feels the kindness around it, it can't help but smile. The final lines suggest a small flicker of hope returning to its roots, giving it a reason to keep going. The mood moves from doubt and harsh judgment to warmth and tenderness. Read this way, the bark can stand for anyone who feels worn or unattractive, and the poem suggests that being accepted by others can bring back a sense of purpose.