/ic/ - Artwork/Critique

What elements do you like/dislike about splash art/promotional digital paintings?
(For example, a scene with battling monsters and heros within a semi-complex environment.)

I read a post here where an anon mentioned that they find all such art grating, so am curious if any of you have any tips as to the nuts and bolts of what elements might lead you to feel a splash piece is either excellent or lackluster. I'm trying to paint such a scene well enough that someone like this anon would honestly enjoy it.
(Mentioning individual pieces you like/dislike would help, too, if you feel like giving visual examples of the sorts of things you love/dislike)