Promotion Materials
From Namco's magazine titled "Nours" (ノワーズ) Vol. 39, on November 21st, 2002, on a section called "Namco Gal's History" (ナムコギャルズヒストリー). Archived on Bandai Namco's website.
Leaked by a 2ch user and archived by ume_black. The images were posted 2 months after release. Notable for featuring the beta designs of Takane and Hibiki.
Photography taken at the 40th Amusement Machine Expo in 2002 (第40回アミューズメントマシンショー) by journalists.
Concept Art
Scanned from "THE iDOLM@STER Platinum Album" guidebook.
Screenshots
Ripped by @saetta06. Leftover screenshots of both Idol Game and the 2003 prototype.
iDOLM@STER arcade 2003 prototype gameplay.
Idol Game screenshots.
Screenshots from Bandai Namco, from blog pages to magazines.
Cabinet
Various photos taken at the 40th Amusement Machine Expo (第40回アミューズメントマシンショー) in 2002 by journalists.
Etc
Old and unused logos.