The advertisement uses source credibility to attract their audience. It uses 'real women' as models instead of 'cat walk' models. This allows the audience to see similarities between themselves and the real women models, thus persuade the audience to buy the product.
Hilmert, Kulik and Christenfeld (2006) showed that when observing a model express liking for a piece of music and the model was similar to the participants, there was more favorable opinion of the music. On the other hand, there were more negative opinions when the model was dissimilar to the participants. So if the audience can see similarities between themselves and the models in the advertisement, they are more likely to have positive opinions about the product.
Hilmert, C. J., Kulik, J. A., & Christenfeld, N. J. S. (2006). Positive and negative opinion modeling: The influence of another's similarity and dissimilarity. Journal of Personality & Social Psychology, 90, 440-452.