Why does not Edmund notice that the White Witch 's smile i'snt so nice?

He is so into the magic Turkish Delight, that he doesn't quite notice the evil or wicked smile.

Plus, it is just a story and that is the way it should go because "The Chronicles of Narnia" is an allegory based on Bible, and Edmund is suppose to be an example of a sinner and the White Witch is suppose to be the Satan.