It’s clear from the cover of The Casual Vacancy that the brief was: make it look as different from the Harry Potter series as possible. A bright coloured background to position it well away from the fantasy gothic genre and some jaunty hand-drawn typography to indicate a warm and accessible tale. There is a hint at politics in the imagery, but apart from that this cover tells you nothing and that, I think, is precisely the point. As a reader you are no closer to the story inside. There is nothing to prejudge or dismiss, it’s just type.