Why are the young trees described as ‘sprinting’ in the poem ‘My Mother at Sixty-Six’?

The poet is in a car on her way to the Cochin airport. She looks outside from the moving car and feels the young trees seem to be running along with them. By describing the young trees as ‘sprinting’ the poet wants to show a striking contrast between their liveliness and her mother’s fading youth.

OR

The young trees running spiritedly in the opposite direction stand in sharp contrast to the poetess’ aged and pale-looking mother. The trees symbolize youth and life, whereas the old mother represents old age and is moving towards the grave. They symbolise the quick passage of time that has brought old age to her.