As Tia mentions in her article, one of the reasons the new cover is able to portray most of the major goings-on in the novel is because of these simple lines. They keep the drawing looking uncluttered, thus allowing the image to contain more details from the book.
One comic that I really enjoy that uses a similar aesthetic--and has a similar effect, I think--is Randall Monroe's xkcd webcomic. While most of Monroe's comics don't directly deal with science fiction and fantasy, many of them do cover topics near and dear to many a nerd's heart--math, physics, computers, etc. And every once in a while, there is one about fantasy literature:

Bill Amend's Foxtrot cartoons also fit into this aesthetic, and while I don't think the simplicity of his characters is used to balance out the complexity of ideas in quite the same way that it is in Brunetti and Monroe's work, it still does make his cartoons extremely familiar and approachable.
In all of these cases, it's an aesthetic that I really enjoy--the simplicity is refreshing, and makes me feel like there's room for me in these images as well.