I get that this is part of a James Dean boxed set, but I don't think it was right that WB emphasize Dean at the expense of Taylor and Hudson, who had much larger roles in the film. (I run an Elizabeth Facebook page, and when I posted the cover art 1/4 comments basically said the same thing.)
While all three of the stars certainly contribute to Giant, I have always seen it primarily as an Elizabeth Taylor movie (though Rock Hudson is great in it, too). I've never been a huge fan of Edna Ferber's "sprawling epics" that cover several generations, including Giant. However, while watching TCM recently, they were showing some promo or other that included images of several stars, and one was Elizabeth Taylor wearing a cowboy hat from Giant. She looked so stunningly beautiful I decided right then that I'd have to get Giant when it is released on Blu just to see one of the all-time great beauties at her loveliest.
I agree the cover art is strange in that Dean is most definitely in 3rd place in terms of importance in the film. I am leaning toward the French box set. As it is a Dean set, the cover art will at least be appropriate for the set.