Ah, I remember where she brought that up. She was referring to this effect:Yuuki said:Her way of putting it was "we don't have a monkey see monkey do relationship with media", that it has a very "subtle and complicated" effect on cultural thinking, etc. She has to avoid flat-out saying it, but at the same time she has to make her video seem relevant to real life....otherwise all her videos can simply be countered with "And?" or "So what?" or "Who gives a shit, it's fiction". I think in one of her videos she said that showing brutalized women in games was irresponsible of developers because of how often women get brutalized IRL, i.e. she attempted to tie videogame violence to IRL violence.
Games and other forms of media do have subtle effects on our perspectives; to claim otherwise is to fly in the face of all sorts of marketing research and analysis.