Cartoons/Comics are a tried and tested way to lift heavy subject matter.
Educational publishers often enjoy seeing pictures done in a light-hearted form. For instance, sooner or later, a classroom debate has to be shown. But it can be done with a new twist (e.g. the Grobby style) while still conveying all the necessary info.
An important aspect of visual literacy is showing kids the conventions of comics, e.g. the speech bubbles, how dotted lines can convey whispers, spiky lines are a shout, bold text is louder and so on. Some of these are shown in the collage with the little Viking girl.