I open Hemingway's The Sun Also Rises at random (chapter 9).
'I haven't seen you since I've been back,' Brett said.
'How are you, Jake?'
Brett looked at me. 'I say,' she said, 'is Robert Cohn going on this trip?'
'Don't you think it will be a bit rough on him?'
'Why should it?'
'Who did you think I went down to San Sebastian with?'
'Congratulations,' I said.
We walked along.
'What did you say that for?'
'I don't know. What would you like me to say?'
We walked along and turned a corner.
'He behaved rather well, too. He gets a little dull.'
'I rather thought it would be good for him.'
'You might take up social service.'
'Don't be nasty.'
It goes on. You see the seeming problem: in theory, there should be some indication of tone, or what they're doing, maybe some gesture, something. But there's nothing. Bare lines of terse dialogue. According to all the rules, it shouldn't work. Only it does, and it's brilliant. We don't need to be told the tone of each phrase - it feels natural, alive. I can hear it, better than I can hear the dialogue in many other novels that "follow the rules".
Why does it work? How does it work? (How does one write like that?)