We can notice that pictorial metaphor works with the advertisements, but the question raises itself "Does the pictorial metaphor work with the political newspaper discourse?"
Take a look on Chalie Hebdo, and you will see a very dynamic interplay between metaphorical and often hyperbolic drawings and a sober critical text. Charlie Hebdo is of course a rather untypical 'newspaper' but a most interesting weekly. This works so well, I think, because thesatirical genre allows much more to be said than what is permitted in the daily papers.
I am Danish, my example was French, which I state in English. Semiotics is international, like the logic of metaphor. Of course, the USE of graphic-pictorial metaphor varies a lot from country to country; but it is always forceful, either as a critical tool or as an instrument of propaganda — the difference may be that the critical use has humour (a sign of intellect), whereas the propaganda version only has pathos. Example: drawing Putin as a rat = propaganda; drawing Putin as God (because he thinks he is above the law) = criticism.