Your delivery changed with the beginning half sounding more static and in the same sort of tone but as you got to the middle, you had more confidence and energy going on. Remember to visualize your audience and how they perceive your delivery and what they are taking away. Try to vary things up and make it unique so that you stand out amongst the rest. Think about an audition and the casting director is listening to hundreds of others. How you are going to make this your own?