This is gonna sound weird, but the expression on her face is so endearing, warm and inviting. Contrasting this with a subject matter that has the potential to be grim, disturbing and saddening, they offset each other beautifully.
In a strange way it reminds me of the many snapshots that friends if mine brought home from their tours of duty overseas..
This is the best character illustration I have seen on here in a long time. The facial expression and the changing levels of detail between the important and not-so-important parts are great. I always have problems of adding too many details in certain illustrations, especially with people (I'm working on it though haha). This is great though