The speaker has inherited a lock box and the money or valuables inside it, left by a man who worked hard and lived honorably. She admits she spends his small savings carelessly, without respect for the effort it took him to earn them. Looking back, she sees him as someone who planted a lonely pine on a bleak hill and found meaning in that difficult act. Her own thoughtless waste feels like destroying what he built.
She cannot understand why she should have his box, since she feels unworthy of even his scant legacy. Yet he is buried nearby, and she has the key, so she controls it anyway. The final image captures her guilt: she is like a person who decorates a sacred tree with cheap tinsel and then throws it away. The mood is full of regret, self-blame, and a sense of sacred trust casually broken.