A little bit about Johnathon's concept art (from an animator!)
These are what we call "thumbnails". They are little sketches we do based on a character's description to explore their appearance. These are different versions of what the character could look like, instead of just Spot wearing different clothes and hairstyles. So yeah, these are not exactly canon. That's why in some sketches his hair is shorter or longer, some straighter or curlier. It's because the artist was still experimenting in this phase.
However, you can see that they are kind of similar in the way that they all seem to have the same skin tone, hair color, and mannerisms. This tells me that the character designer who did these was given a very specific direction to follow. Usually the more important the character is to the plot, the more details you'll get before doing their design.
I'm guessing this character designer received something like this:
"Johnathon Ohnn is a white man in his late thirties. He is (insert height here) and a little chubby. He has long brown hair and a scraggly beard, and wears glasses. He is a scientist and a bit of a hipster. He is messy and always tired from work."
These notes are probably adjustments. Character designers usually make a first batch of thumbnails and then get notes from the art director such as "please use 1's hair with 4's shirt", or "can we get him wearing different pants?"
The first designs of a character don't need to be perfect (and no one expects them to). You just need to know how to develop your idea to get to the final product.
THIS is (most likely) his final design, because it shows up in the movie (if not with a slightly darker skin tone). In my experience, sometimes designs change when the animators are already doing the finishing touches on their scenes. Who knows on what point in production this illustration was made? I'm just guessing based on the information we have.
That being said, just because the thumbnails aren't canon, doesn't mean you can't use them as inspiration for your art or fanfiction. My fic's Johnathon has 2's tattoos for one.
I also always treat the character designer's work as word of god instead of what the executive's paying for the movies decide will be aproved or not. Sometimes a character may have their whole face changed because some boomer guy in a chair says it will make the movie sell better. So fuck them executives!!
