Does the game come with some kind of a digital art collection of all the card art? This is very frustrating because WOC does not release any kind of artbook for their art.

Nope, but you can extract... let me check... 37 artworks of various cards that are used as loading screens. All in a 1280x720 resolution.
(I have a Rath Cycle artbook here. So much about never releasing something like that.)