Hello Maggie,
The Paris Review is an American literary magazine and this is from
an article about the writer Flannery O'Connor.
Bailey in “A Good Man Is Hard to Find,” with his bald head and Hawaiian shirt, and the children’s mother, whose face, “as broad and innocent as a cabbage,” is tied off with a green scarf that has “two points on the top like rabbit’s ears”—all have the appearance and substance of animated characters in a cartoon script for 1950s suburbia, complete with a couple of bratty comic-book-reading kids in the backseat of the car.
You may not need telling these things but we probably do.
The quote is being used in the sentence to suggest that Miss O'Connor was trying to make her characters in this story seem like figures in an animated cartoon. She was, after all, a cartoonist as well as a writer.
It might also be worth mentioning that serious writers are often looking for striking images, to avoid cliché, and to find new striking ways of communicating ideas. Here Miss O'Connor seems to be striving for a particular literary effect. Her simile should not be examined in isolation, but considered in its context - the story, not the article, which is about Miss O'Connor's writing in general.
Cabbages are round and featureless, and not obviously guilty of anything (as Keith points out). Miss O'Connor knew about cabbages.
I don't think this has anything at all to do with French. Miss O'Connor suffered from systemic lupus erythematosus and lived most of her life on her family's farm in Georgia. Her writing is deeply American, of the South. I don't think she ever left America.