[ashlar]

You can change the artwork from the information dialog.

For the container, containing the different versions you can. But I don't see a way to select art for the different versions of a movie. This is what I am referring to. Once you select "show versions as folders", that is. You "go in" and you see the versions listed. But their artwork basically disappears.

I have tested this again before answering you.

EDIT: I see you have Alien in the test screen you posted, with posters and fanart... well, I get this and I have no way to change it. And, before, the separate movies had correct art.