They are visually appealing and are technically implemented nicely. I think, however, that they are not very insightful to the matter. It is easy to visualize the result of a BGP hijack: packets are routed to the wrong/malicious destination; so is visualizing the result of RPKI: packets aren't routed to the wrong destination.
What, to me, would have provided a little more value would have been to diagram how BGP hijack happens (visualize a router announcing the wrong route), and how RPKI solves the issue. Of course, those 2 things are probably much harder to diagram.
edit: re-phrased a sentence.