I think that it is the hand sweeping movement.
Answer:
We can apply it to our own lives because we've all done mistakes and bad things in our lives but we can change our ways for the better like how instead of becoming a greaser Johnny believes that Ponyboy can become good in the world. It kinda shows how in life some people have done bad things but if they change their ways starting now they can still be part of the good in the world. I hope this helps :))
Authors use figurative language to make their writing more interesting and to more easily communicate an idea that is not easily understood because it may have an abstract nature or complexity.