I found this metaphor to be a little ridiculous but exceptionally representative of the character. Throughout the commercial, the deaf girl was always told her limits. Her peers would not allow her to discover her true potential as a violinist. Once she met the deaf man who played the violin on the street corner, she was inspired to pursue her dream. By the end, she played the violin at the concert and received a standing ovation from the audience.
Although I found the comparison to be slightly cliche, I could see the connection well. I feel that the butterfly introduced the audience to the feeling of beauty, so shortly after it would be easier to recognize the beauty of her hair. The audience was already open to the idea of beauty. Also, the butterfly is the logo for Pantene. Once knowing the connection of the butterfly to Pantene, it became easier for me to recognize why it was included in the comercial.