I apologise, I was not implying that Yoshimi should use anything other than original art, especially not copyrighted material; I was offering the cultural context that this page says the name 'Yoshimi' lives in. Some artifacts could serve as inspiration for potential artists, such as colour scheme or sense of silliness, but the ultimate splash screen must be novel.
Sorry, I understand bad the original propose of a splash screen.
A splash screen is a roughly window-sized piece of art that is 'splashed' (displayed as immediately as possible after the user attempts to start the application, for example by clicking a desktop icon) on the screen until the program has finished loading all of the components it needs into memory and is ready to be used. The contents of the splash screen have enough detail and visual interest to give the user something to examine during the program's loading time. This was a common practice ~20 years ago when many graphical applications took at least a few seconds to start up on the hardware of the time, but it remains popular even now that hardware advances mean that most applications start almost instantly. The splash screen, given that is has a lot of screen real estate to work with, is a chance to communicate the character of the software it represents (some of which Abrolag communicated in the email before last). It is also an opportunity to display some information the user might want to know, like version number, development news, tips (like KDE applications often do) and so on.