My guess is, after having done something similar, is that this is all strip pieced like a bargello quilt. Take a look at the center which is a big bargello square on point. Then the outside is another bunch of strips, and so on. Although easy isn't what I would label it, when you consider it from a certain point of view, it is a simple bit of cutting strips sewing them together, cutting them again and then doing the bargello dance. Of course that alone can make me crazy.
All in all, it's such a cool looking quilt. My kids (all adults now), would love this.