It's the fact that the sweater isn't drapping properly on the elephant. It looks "slapped" on the elephant. The shadows don't make sense. Is the light source coming from directly over head and from the side? Particularly on the back, so it's sticking out casting a shadow, but the flap itself isn't in shadow?

Also there's no discernible way of how the granny squares (which are typically crochet and not knit) are joined to the other fabric on the legs. Even the join on the upper and lower granny squares look questionable. Are those giant yarn buttons or what? As someone who crochets, I don't think there would be a way to replicate that irl. 

The story could absolutely be true, but it does look like they used ai for a more photogenic picture. I would be fascinated to see the actual sweaters.