I'm glad to hear you're feeling better

LOL at people reaching for some deeper meaning simply because a film is European, it's just humour for Christ sake. Also the line was "Happy to hear you're doing fine".

If you want to take it literally, it just reflects the often monotonous and superficial tone of our conversations. Also ironic it is often said by people themselves who are miserable and are unable to express this.

The word fine is used instead of better but either way Andersson is exploiting it to shows the emptiness of human conversation and relating. Fine is a word used as a platitude.

In the midst of winter, I found there was, within me, an invincible summer