Are you aware that the Kindle usually opens to the first text page of a book**, and you have to purposefully LOOK for the cover page***? It does not show you the cover of most books, unless you open the menu and look for the cover. That doesn't mean the cover isn't there. It means the Kindle programmers think you want to immediately start reading the book. (It may mean they aren't readers; I'm not sure about that!) I almost never see the covers of my books, because I never think to manually look for them.
This doesn't really answer your question, but it may bump the thread and draw some more attention to your question.
** Or at any rate, what has been designated as "the beginning".
*** Or unless you page backwards from "the beginning" to look for the cover.