Question

The clock in the hall did not strike; it simply allowed the hour to dissolve. Eleanor watched the shadow of the elm stretch across the Persian rug, a slow, dark finger marking the retreat of the afternoon. It was the same rug her mother had brought from Smyrna, smelling of camphor and salt, though now it smelled only of dust and the cold tea left on the sideboard. 'He will arrive by the five-forty,' she told herself, though the letter in her apron pocket was already three months old, its folds soft as cloth from her constant, secret touch. She remembered the station at Dover—the steam rising like white breath in the chill November air, the sudden, sharp whistle that seemed to tear the morning in two. He had not looked back then, or perhaps the fog had simply swallowed him before he could. Here, in the quiet room, the ticking of the mantle clock grew louder, a mechanical heartbeat filling the silence left by his voice. She stood up, smoothing the front of her skirt, and went to the window. The street was empty, save for a boy trailing a stick along the iron railings, the sound rhythmic and hollow. She would wait, as she had yesterday, and as she would when the elm shadow finally touched the baseboard and left the room in darkness.

Which of the following best describes the narrative function of the temporal shift from Eleanor’s present anticipation in the room to her memory of the Dover station?