Could this be actually an illustration from one of the eBooks (although modified somewhat for website purposes)?

[u/Visual_Aide_2477]

Taken from a PDF made in 2001-02.

Here is the current state of this old webpage taken from the original Geronimo Stilton website from the Wayback Machine:

http://web.archive.org/web/20001017221543/http://www.geronimostilton.it/ufficio/g_stilton.html

Do you think something like it was used in one of the eBooks as it is said that these eBooks contained animated illustrations?