It scared him that she saw his soul and not the broken man he felt inside.
If he couldn’t live up to how she viewed him, then surely, she would leave him one day when she finally realized that he was “only” human.
The one thing he couldn’t see as he walked away, was his own soul that was trying to shine through.
The soul that she could see as plain as day.
In that moment she realized that it is just as important to recognize the fallible human being as it is to see through to the soul.