It would definitely be criticism. I have a tendency to criticize certain things that she likes and that rubs her the wrong way. It's hard for me to not judge things like TV shows, movies, or music, etc. simply because those things are mostly designed to be judged by others, but doing it in a constructive manner is the key I suppose.
I will say one of the things I will love to change is my hot temper. As I am easily prone to anger. My partner have complained a lot about this and I still find it a little bit difficult to change but if I am able to change my hot temper, she will really be glad of it.