These are really cool guys. @Braden-Hallett I think you have WAY more detail in your backgrounds that any graphic novel my kids read, so you probably can dial it back even to save time (unless you love doing it hah).
@kylebeaudette back to your initial question - I'd personally say it's both. Depending on the style of a picture book, your first image actually looks like something you might find depending on the style. I think it might just depend on what's specifically trendy at the moment (or what look the author had in mind).
I really gotta make a project to try and get into one. The age group really interests me because all my kids are reading this kind of stuff today. Plus, doing stuff at 60% is so my jam with how busy I am these days lol.