The Don loves women and leaves them, without any care for social conventions. While Leporello's decision to not engage in transgressions with women may be class-based in some instances, even the Don's higher-born counterparts do not openly defy conventional sexual wisdom to the same degree as he does. The celebratory and openly joyous nature of the "Madamina" aria is a kind of celebration of sexuality members of the audience may wish to engage in, but do not. Despite the literal word-painting of the appearance of the blondes and brunettes, there is a stark contrast between the 'mind in the gutter' literal wordings of Leporello's leering commentary with the agile beauty of Mozart's music. Elvira is silent throughout the aria, conveying her sense of resistance and disgust. The audience cannot completely side with her. Rather they stand betwixt and between Elvira and Leporello. They cannot wholly condemn the Don just yet, given how he enthusiastically seems to lust after all women, fat and thin, young and old, even though they may express some sympathy for Elvira. For the opera to 'work' and to keep the audience's interest and attention throughout its duration and the journey of Don Giovanni's life and death, the audience must sympathize with its title character to some degree.

This...

In a recent performance by Luca Pisoroni as Leporello, the actions of the opera were transposed to a vaguely late 20th century. Instead of a thick book full of women, Leporello showed Donna Elvira Kodak Polaroid photographs of the different women Don Giovanni had loved, taken from a photo album he carries around. Instead of period costumes, the two singers are in trench coats, and Elvira has her hair fashionably cropped, as if she is a flapper. To underline how Leporello identifies with Don Giovanni, as he sings to Elvira, he holds her in his arms and lovingly places the photographs through her pained and tormented face. The effect of the aria, regardless of setting is the same, however -- even if Elvira walks away in anger and pain, the audience, at least for a time, is won to Don's side, by virtue of the persuasive enthusiasm of Leporello.
Works Cited

Fisher, Burton D., ed. Mozart's Don Giovanni (translated from Italian and including music highlight transcriptions). 2002. Opera Journeys Libretto Series. Coral Gables, Florida.

"Madamina" from Don Giovanni. Sung by Luca Pisaroni. July 2011.

Retrieved from YouTube, November 2011:

http://www.youtube.com/watch?v=2QHvWxNF2MU&feature=related