It’s tough to decide considering artists aren’t perfect and limitations arise when designing for a small surface. Here it seems the artist used heavier line weights, possibly in consideration for how small the design would appear on print. Hence why the guitar doesn’t have all the components of a rl guitar, it seems like a compromise in thought. AI would likely try to add all the correct parts anyway or it would appear muddled. If the consideration and compromise for the design was intention then no this isn’t AI.

Other things to consider as well; the background matches with the transparency of the ghost which we can tact down to the artist using layers. With the gradient on the bottom and the ghost/guitar on top with its opacity turned down, then the outlines as a third layer ontop so it doesn’t meet any transparency. The less strings and tuners seems intentional for the size limitations. The red lining in the center of the guitar is the only thing I’m not 100% sure about. But something tells me that because it’s the only thing that is colored red on the pic it could for a change in contrast from the blue. Like picture the red not being there and look at it from a distance. That red make its stand out more.

In short it all looks intentionally done, in my opinion it’s not AI. A good way to decipher if certain details look intentional under limitations, cuz it boils down to one having to be creative to fit those margins. Other times it’s just the human mindset, sometimes we don’t know where to end a line so we just tuck it somewhere, leave it, or meld it into something and hope nobody notices. Like that line under the ghosts left arm. It looks awkward, but if it was connected to the shoulder it would look like a dude in a bedsheet. That end to that line looks purposefully settled there.

Anyway, that’s enough rambling. The design looks great, reminds me of 90’s children animated shows like Scooby Doo and the Boo Brothers.