Actually, I think it's the album jacket that's solarized? I'd have to read the blurb again, but I know that in addition to the lithograph, the album jacket artwork is being presented as initially envisioned by the artist, which is somehow different than how originally presented. (Not to suggest that this justifies the cost, but it is something unique about this package.)
EDIT: Here's the relevant language from NY's site:
The artwork for the album is updated for the 50th Anniversary Edition:
- In the years before he passed away, Gary Burden, Neil’s long time art director, had envisaged solarizing the album art – especially the back cover shot of Neil’s jeans & patches. Gary’s partner, Jenice Heo, has now executed Gary’s vision and created a unique take on this classic album cover. The cover is printed on special silver coated paper stock to create the desired effect.