Women are often advised to cut their hair short for better success gaining employment. Michelle Bachman is criticized for spending too much money on her appearance, as if caring that much about one's appearance makes one a poor leader. Hillary Clinton is mocked for being too masculine. And in the Legally Blonde movies, Elle Woods is assumed to be stupid, simple minded, and unable to succeed in law or politics because of her overt femininity.
Too often, if a woman shows her femininity, people assume she is stupid. I'm not immune to this thinking: sometimes I see a group of girls in super girly clothes, giggling and squealing together, and annoyed, I roll my eyes and think "please God, save me from the stupid." But it is problematic when we see femininity as being incompatible with the workplace, or at least most workplaces (often femininity is seen as compatible with working in industries such as fashion or wedding planning, which happen to be frequently recommended careers in young women's magazines). This is because the underlying assumption is that being a woman is incompatible with being successful in the workplace. Naturally, people still make jokes that PMS, and women's assumed emotional tendencies, interfere with a woman's ability to do her job.
Feminism isn't about eschewing femininity with a strong hand and encouraging women to be "like men," nor is it about compelling women to be "true to their gender" and embrace femininity. Rather, feminism is about believing that there is no right way to be a woman, that how feminine a woman is in her presentation should have no bearing on her perceived ability to be successful in her career. That a female politician's support should be based on her politics, not the length of her hair or the silhouette of her suits.
To me, the Legally Blonde movies don't idealize femininity, nor did they ever make me feel bad about the way I look. Rather, they taught me that whether I wear black or pink, I can kick ass in anything I choose to do.