A hodge-podge of strips and sundries that hadn't been collected anywhere else, along with snippets of contextual-historical background essays. Far from comprehensive, but certainly interesting and educational. My understanding of the decade before the military junta took over in Argentina was pretty much a void, and the cartoons and the historical essays helped fill me in a little better. I also feel like I got a slightly better sense of what the newspaper-reading class in the Southern Cone thought about their region and world events from the early 1960s until the early 70s. Now I want to get my hands on some of the regular Mafalda collections.
There's always so much creative language usage and Argentine slang in these cartoons that I need to have a dictionary on hand. Which I didn't have, since I was traveling, so I only got about four fifths of the jokes. [Comedy, to me, is always the hardest thing to pick up in a foreign language: it's a sophisticated, complex set of references and inversions of everyday language that I think shows just how brilliant people and jokesters are. Ironically, theoretical, journalistic or technical writing can be pretty dry and straightfoward, making them much easier to approach.]
It turns out that Quino was doing the Bill Watterson/Gary Larson/Aaron MacGruder thing long before they did; that is, carefully crafting a popular, beloved strip but realizing that it was time to pack it in before too much time went by. Homeboy wrapped it up after nine short years. Of course, in his case, it may have had more to do with the scowly gentlemen in uniforms who thought the Nazis didn't have the wrong idea when it came to handling commies, cartoonists, and other hooligans.
...Woah, I just checked out the current English Wikipedia page on Quino (Aug 23, 2008), and it is TERRIBLE. Just three paragraphs on what his cartoons are sort of like and what the overall themes of the strip are with no real history or specifics.