I've seen white Blu-ray cases but they were the thinner ones they use in France. I can't really tell from that pic if it's a standard UK-sized (14mm?) case. That being said, clear cases look better imo.
Comes packed in a rigid case with the Blu-ray disc house inside an amaray case. Also inside the rigid case will be 6 art cards and a booklet that contains background information on the film along with an article specially commissioned for Anime Limited.