Jess becomes more imaginative, and Leslie becomes more compassionate. They each teach the other about becoming a better person.
In teaching Leslie compassion, Jess strengthens his own capability for it, and in leading Jess into Terabithia, Leslie expands the boundaries of that realm for herself. They learn to see other people as their friend sees them.
The simile of Lines 18 through 23 compares the storm clouds that whip across the sky from the horizon to the zenith to: locks of hair of a frenzied woman. (Ode to the West Wind).
