The hidden meaning of headlines

A lot of English and American newspapers are read by people who, although they have a well-nigh perfect command of the language, are not themselves English or American or perhaps have been born and raised in another country. I am referring to the sort of publication which is aimed to a greater or lesser extent at an international readership: newspapers like The International Herald Tribune and The Washington Post, magazines like The Economist, Time or Business Week. I wonder sometimes what such people manage to make of some of the headlines to articles and stories.
Here is a list of such headlines taken almost at random from the latest issue of The Economist
Hot on the press
Barbers at the gate
Going out in the midday sun
The blackened sheep
Blood and treasure
Cheques in the post
Who's afraid of Daniel Ortega?
There he goes again
Trouble at till

Any reasonably well-educated person born and brought up in England or the States will immediately recognise the allusions behind these titles (an Englishman might have trouble with "There he goes again", an American probably with "Trouble at till").
The thing is that none of these expressions are really what you might call idiomatic terms, the sort of thing a proficient foreign speaker might be expected to assimilate. They are simply part of our culture, distilled from school, books, TV, the news, etc.
So what is your point?
I don't know, really, but it's interesting just the same.
To finish, here's just one example of what I'm driving at. My son-in-law is French. For the past five years he has been living in Houston, Texas, and working for Mckinsey's. His command of English is truly excellent (otherwise he wouldn't be in his job). The other day I asked him what the figure" 57" meant to him. I'm prepared to bet that any American or even English person of my generation and perhaps more recently, would immediately think of Heinz - a company which has had only limited success in France.... But of course my question drew only a blank stare from my brother-in-law
I suppose what I am really trying to say is that there is a "deep culture" attached to a language which those of us who acquire mastery of its "external trappings" are never even aware of.