Yes, the portrayal of women have a negative impact on our lives. This is because when a girl/woman sees a photograph of another woman posing/taking a picture, and if that woman happens to be society's definition of "skinny", then another girl/woman might get jealous, and may force herself to be thin(ner), even though they already are.
Media gives us unrealistic standards, the amount of girls I have seen who want to look like the woman in the magazines is unreal. They have been airbrushed etc, girls feel increasingly negative about their bodies and this has led to an increase in eating disorders and mental health issues. Not good!
Showing beauty in all its forms is a great benefit of mass media. But when it tries to manipulate that beauty in an artificial way and hold up only certain forms as beautiful, as it does with women, it is very harmful. As a woman I understand the terrible standards to which the average woman is held and holds herself because of this.
Women in the mass media are being portrayed more strongly today than ever in history. For example, shows like The Good Wife and Nurse Jackie portray strong, beautiful, career oriented women in a great light. These and other portrayals positively impact our lives by setting a good example for girls and women and smashing stereotypes.