A small detail that I quite like, though I'm not sure it's intended to be canon, is that the black band around Thornax appears to be added to the fruit to facilitate its use as ammunition, and not something it has naturally.
Like in the sets, that black band is a track where the arms of the launcher are meant to hold. It's harder and smoother than the golden "flesh," which is made of a different, rubbery plastic. If you put the Thornax in the launcher the wrong way, so the arms are holding the golden part, it won't fire, it needs the smoother, raised surface to effectively launch the ball. That is explicitly what that band is for irl.
But judging by this image, it's possible that even in-universe, the same is true.
Granted, the image is stylized and silhouetted, but setting that aside for the moment. Notice how the fruit appears perfectly round, no raised ring in sight.
It's absolutely a very minor thing, but I don't know, I love small details like this that make the world feel more lived-in. You can't just pluck a Thornax off the vine and load it in your launcher, it has to be prepared for the arena and fitted with a launching band first. I think that's neat.
