I just started a replay of RF4 and I was immensely disturbed by Xiao Pi or however you spell her name's intro? I don't remember her butt squishing against the screen and I just have to ask... why? What were they thinking? And what sort of perspective would the protag have to be looking from to see her butt squish against the 3ds screen. It was very, as Arthur said, meta. Overall, I am freaked out.
Might just be a Japanese culture thing, if they get a kick out of that. Having her fall shows us that she's clumsy, but specifically having her butt land on the camera is pretty repulsive or distasteful, at least for me.
Hopefully she didn't actually land on top of the MC's face...