The moon is lit from the wrong side and it has a crescent shape in what's basically an overhead projection. And it's not like there's much else going on in the illustration, it's one of its main elements.
You're not wrong, and for the amount of effort put into this presentation, I'm surprised at this oversight. But if you can think of this image as a schematic, it's not a huge problem.
That would imply a student being towards the upper end of the age cut off for starting kindergarten/elementary school (in the US at least, varying by state).
The initial diagram showing new/half/full moon goes off my screen, presumably because I'm at 150% desktop zoom and it possibly somehow gets confused by that?
Also the feedback about the wrong side being illuminated.
The moon is lit from the wrong side and it has a crescent shape in what's basically an overhead projection. And it's not like there's much else going on in the illustration, it's one of its main elements.