H.R. Giger, the famous creator of the Xenomorph in the science fiction classic ALIEN, was also part of the all star team that worked on Jodo's Dune. The enclosed design of the castle fits perfectly with the description of Harko City in the books, which is probably just a happy coincidence. The elongated back of the head is an obvious resemblance to the aforementioned Xenomorph.
He actually made a harkonnen chair prop fit the film which I once saw at a sci-fi exhibition. There may have been other props he made too, can't actually remember. Got to see some of the Alien space suits too. They were cool.
Yeah! https://en.wikipedia.org/wiki/Harkonnen_Chair