I love the art style and facial expression. It feels like a very relatable moment - like when you hear something wild in public and can't help but turn to look.
You are right, The reference photo didn't have too much detail on her face, it was a wide angle shot from distance and she was having a look back while walking on the street.
If there was more contrast on the face (so it’s less flat) and thicker eyelids (less white of the eyes as well or maybe they’re too uniformly white), I’d wager the face would “pop out” more.