If anyone wants to know more on the image source: I knew that this is illustrated by ixima, but its quite old and most search results give nothing helpful. The four more "proper" sites I found are sankaku, e-shuushuu, zerochan and vocaloid fandom wiki, but none of them provides direct source. Luckily through a reverse image search with ASCII2D I was able to track this old Tweet of ixima that appears to have the exact same image size, which seems like a legit origin. Unfourtunaly it's not available anymore, so I uploaded the zerochan source as it contains both the clean illustration and the novel cover variant.