How does Brian Greene use imagery in The Elegant Universe: Superstrings, Hidden Dimensions, and the Quest For'?

Example of Imagery:

"Physicists are more like avant-garde composers, willing to bend traditional rules and brush the edge of acceptability in the search for solutions. Mathematicians are more like classical composers, typically working within a much tighter framework, reluctant to go to the next step until all previous ones have been established with due rigor...."