How do the similar expressions below can be distinguished from one another?
If you describe a person or their behaviour as icy, you mean that they are not affectionate or friendly, and they show their dislike or anger in a quiet, controlled way.
A cold fish:
If you say that someone is a cold fish, you think that they are unfriendly and unemotional.
These two idioms, mean exactly the same to me and I need to inquire whether I am right or not. I wonder if you could explain that to me.