why was the AI image rejected?

The top part of the apple has a drawing error, she’s missing some fingernails, and it looks like she’s floating above the branch rather than sitting on it.

Choose one, fantasy or photorealism. Combing both doesn’t work aesthetically. They’re too far apart.

The plastic fairy doll looks out of place against the natural tree.

She might work better in a fantasy mushroom garden.

Or find a more human-like fairy to replace her.

You might also want to consider local editing to improve details. Here, the pattern on the shoes is improved and the buckle is more accurate. 
 

A couple things stand out: