Huh, I would have figured that these artbooks would already be here. Especially when Noizi Ito got extra attention from the Shana and Haruhi animes. I've had scans of them for forever.
https://shakugan.fandom.com/wiki/Kaen "The book features around 100 illustrations of Shakugan no Shana. These include illustrations of Shakugan no Shana VII to X and 0. It also features promotional posters, art from the ending themes of the anime, and other anime illustrations.
There is also around 50 illustrations of Shana featured in the book that were posted to the newspaper Mainichi Shimbun's magazine for anime, manga and games, Mantan Broad, as well as other illustrations by Itō that were used in Dragon Age Pure, as well as images from Itō's manga, Bee-be-beat it! and the ending theme illustrations of Tsukuyomi: Moon Phase. Other featured illustrations were posted in to Melonbooks Inc., Comic Toranoana, and K-BOOKS.
There are an additional 30 illustrations which include the light novel covers and illustrations that weren't included in the light novel volumes.
Lastly, there are illustrations by the friends of Noizi Itō who are congratulating her, such as Shōko Nakagawa. Ayato Sasakura (the illustrator of the manga), included illustrations which are either from the manga or original. Shii Kiya (the illustrator of Shakugan no Shana X: Eternal Song) also included illustrations.
There is also an original extra story included by Yashichiro Takahashi, called Kaguya-hime no Shana (かぐやひめのしゃな?, Shana of Princess Kaguya) which is a reference of the Japanese folk tale Princess Kaguya. "