From Works of Wonder:
"Since I did the eleven books over the course of a year, as time went on some things became less important. This time we did not worry about the title of the book, and Llana herself does not even appear in my painting. I realized that after doing nine covers I still ahd not shown one of the unique Barsoomian airships so commonly featured throughout the series. To tell the truth, I felt there was little point in doing so, since Robert Abbett had done such a great job visualizing them on the covers he painted for the books in the 1960's. Nevertheless, this scene involved an airship and also conveyed the feeling of the book very well."