Cat Scratch Fincher

So I was gonna write a non-spoilery review of Gone Girl about how it's really an HBO series packed into a feature film because of the weird episodic structure which doesn't really obey any sort of normal act structure.
Then I was going to write about how the cat in the movie was a cat from some romantic comedy thrown accidentally into a thriller picture and nobody really knew what to do with the cat once it had seemed like a freaking plot point to feed the damn floppy thing.
But that's not what I'm going to write about. No.
Instead I'm going to write about the gratuitous thigh scratching.
Look, I have to sit though tiresome essays like this one. Ooh. Fincher doesn't use closeups when he doesn't have to. Oh yeah? Then explain the thigh scratch to me.

Maybe the whole thing was a goof. Maybe the cat was really Jonesey from Alien. Maybe it's Fincher's apology for ruining the Alien franchise.

Also, this movie just wasn't directed at all. Everything about Gone Girl was on the writer. As a movie it didn't really need a director. Any competent cinematographer with a competent AD could have got all the shots they needed and then sent them to editorial.
But that's not the point. The point is that we cut to the closeup of a thigh. Being scratched.
Why?
That closeup actually makes me angry. I should go lie down.