The Good Will Logo exemplifies the Gestalt principles repetition and closure. The Logo exemplifies the good in Good Will and is memorable.
The similarity/ repetition in the logo is with the g and half of a “face”, the two are the same shape. It isn’t something that you immediately identify but it keeps the design simple. The continuation in the logo has to do with the larger g shape; most people don’t identify that as a G but fill in the space mentally and see a smiling face.
The smiling face shape makes us see Good Will in a positive light; they help people and make them happy. If we didn’t perceive the large G shape to be a smiling face our reaction to the logo might not be as positive. The repetition of the shape keeps the logo consistent. It’s important the Good Will logo appear clean and simple so that we trust that it’s a well-run and organized organization.
In all I think that the Good Will logo is a clever design and represents the Good Will brand well.