The ethical dilemma posed in this poem--that is, whether the children would save the Rembrandt painting or the old woman from the fire--is actually unanswerable.  This dilemma itself is symbolic of the inability  to find easy answers for life's hard's questions. We know that the classroom activity is itself a kind of fantasy (and therefore potentially symbolic) because the child returns to the same class and the same teacher every year.  The colors of the painting are also symbolic of life: "earth's most radiant elements" found in the painting, the season, and the old woman.  The poet, wiser in her older years than in the youth she looks back upon, notes that "woman / and painting and season are almost one / and all beyond saving by children."  The closing lines reinforces the symbolic nature of the dilemma itself and the impossibility of answering it.