Columbia's typeface has dark and light areas which makes it look 3-Dimensional and chiseled. This is similar to how I have used the shading on my typeface.
Last year John Rocco was approached by DisneyHyperion to redesign the covers for the Percy Jackson & the Olympians series. Rocco said on his website that it is very rare that the original illustrator to be asked to redesign their own work.