Please help me I have a senior deadline. I know that the sentence in between the em dashes restates the first part of the sentence, but how does that affect the rhythm and overall fluidity of the sentence? Thanks
(Shooting an Elephant)
"When I pulled the trigger I did not hear the bang or feel the kick—one never does when a shot goes home—but I heard the devilish roar of glee that went up from the crowd. In that instant, in too short a time, one would have thought, even for the bullet to get there, a mysterious, terrible change had come over the elephant."

In three to five sentences, explain the methods used by the author to create sentence fluency and rhythm in this passage.