A father looks at his son, who is the image of him, and feels proud and glad. But the poem soon turns to something he regrets. His son once asked why he had no brother or sister, and although the boy has stopped asking, the speaker still sees the question as a shadow in his eyes. The father says a decision like that can't be undone, because life isn't a film that can be rewound.
From there the poem drifts into imagination. He sees a little girl with a ponytail, a pinafore drying in the sun, and a pair of hands covering his eyes. He pictures her wet hair, her anklets, her laughter. These details feel tender and vivid, yet she is only a daughter he invented. The mood is wistful and gentle, with a quiet ache under the warmth. In the last lines he leaves the doors open at evening, still inviting this unborn child to come in with the light.