You're worth it... Okay then, take my money!

In this L'Oreal ad related to all their 'because you're worth it'  catchphrase campaign, the girl is talking about beauty and what it is to her, mostly as "being in her own body confidently" and "knowing that she's worth it".

The technique used in the ad is called flattery. Hendrick, Borden, Giesen, Murray and Seyfried (1972) did a study on flattery. They mailed a questionnaire to 400 subjects, asking for one of two things: a) a small request (a one-page questionnaire), or b) a large request (a seven-page questionnaire). Both of the questionnaires had a cover letter attached to it. There were four types of that cover letter – a) the subject was flattered, b) the sender flattered themselves, c) both the subject and the sender were flattered, and d) neither the subject nor the sender were flattered.
The results have revealed no significant differences in returns for the small request conditions. However, an important finding for the returns of the questionnaire was that it was significantly higher for the large request but only in the situations were the cover letter consisted of flattering only the subject or only the sender (.29 and .24, respectively, compared to significantly lower .08 and .10 for double flattery or no flattery conditions). The results for the returns of the questionnaire can be seen in Table 1.

As the girl in the advertisement is flattering herself but does not explicitly flatter the viewer, she falls into the 'sender-flattering' condition, making L'Oreal products flattering to the eye or for the purchase, too.

Reference:

Hendrick, C., Borden, R., Giesen, M., Murray, E., & Seyfried, B. (1972). Effectiveness of ingratiation tactics in a cover letter on mail questionnaire response. Psychon Sci, 26(6), 349-351.