It may not cause an obvious, physical result. The problem is that the change is often more insidious and affects the lazy part of your brain that likes to immediately reaffirm things it already believes. For example: The thought experiment involving the child who gets in a car wreck with his dad, and the doctor says "I can't operate on him, he's my son". I have yet to meet a person who automatically is like, "Oh well duh, it's the mom!" Usually people are like, "Huh? What? How?" If you asked a person on their own, "Are there female doctors?", they would definitely say yes. But this experiment taps into the part of your brain that assumes and makes quick judgements, so unless you have a lot of experience with female doctors, the answer doesn't come to you right away because your brain equates "doctor" with "male".
How does this relate to videogames and other popular culture? Well, the more you see a specific gender in a certain role, the more you associate that role with that gender. You do this subconsciously. If you see ten male nurses and one female nurse, you can get the opposite effect. Your mind makes quick associations with what it's familiar with. So if you see 100 sexy women for every 1 "normal" one, the normal one is the one that feels weird, and to think that this does not extend beyond the media you consume isn't realistic. Yes, these are short, fleeting thoughts, but they are still thoughts and they build on themselves. Morrigan's picture of the "sexy dudes" is a perfect example of this.