From the interview [1] - twelve of the images were originally used in a calendar application called "Seize the Day" [2][3] and later modified and used again in "Magic the Gathering: BattleMage". Other images were concepts for games that never made it to production.

[1] http://www.effectgames.com/effect/article.psp.html/joe/Q_A_w... [2] http://www.iangilman.com/software/seizetheday.php [3] Free and available for download here: http://everonward.webs.com/seizetheday.htm (OSX OS9 XP)