Backwards-Running Clock
The backward-running clock is a symbol of the loss of young men in World War I. To remember them and to wish that time could go back, and bring them home to work and live full lives which were taken far too soon, are among the meanings that this clock signifies.
Yellow
We see Daisy twirling into the street in Paris in a yellow frock coat before being hit by a car. The yellow symbolizes that she was at the height of her vibrance when her leg was crushed, thus ending her dream.
Hurricane
We see the clock that runs in reverse still ticking in a warehouse as the hurricane warnings blare, telling everyone that the storm is here. It is a symbol of how time is forgotten and the things that symbolized great meaning for a generation are no longer remembered, but wiped away.
Stockings
We see Daisy unrolling her stockings as she and Benjamin become intimate for the first time. As she does so, she reveals a giant scar on her leg. This unveiling is a symbol of her revealing all of herself to Benjamin for the first time in her life.
Capturing the Moment
Benjamin asks Daisy to stand with him in the mirror of her dance studio looking at them. He wants to remember this moment forever. It is a symbol that this is the happiest he has ever been and he knows this moment is quickly fading for the two of him, as he will soon grow younger and younger as she grows older and away from him.
The Hummingbird
The hummingbird is the only bird that can move backward. It not only symbolizes Benjamin's life, that he's living in reverse but also bears a strong message for the audience that even though one always can look at their past, they must not dwell on it. It complements the other symbols in the film that represent the past like the clock that runs backwards. The fluttering wings of a Hummingbird form the symbol of infinity, symbolizing the idea of perpetuity and in the words of Daisy, one of the few things "that last forever". Benjamin ends up writing in his diary perhaps to preserve the details of his life, and to internalize them for his daughter.
