A different perspective on the movie, Gone Girl (spoilers obviously)

Sorry if this has been discussed before in an earlier thread, I searched but could find no match.

Most people were disappointed with the ending of Gone Girl. Mostly with how Amy didn't receive justice for being the psychopath that she was, and how nothing was really resolved. I talked to my friend about it last night, and he put a whole new perspective on the ending.

He said Amy didn't get away with anything. The whole movie was thoughts in her head. If you remember, Ben Affleck said in the begginning of the movie that he would crack his wife's lovely skull unspooling her brains to get answers. The whole movie was finding out what she was thinking about how killing her husband would play out. At the end of the movie, it's the same shot of her lifting her head as she does in the beginning of the movie.

Anyone believe this is what the director meant? Makes perfect sense.