The brooch is a 1 5/8" circle. Four different designs have been sewn together and folded to create a dimensional half sphere. Instructions with step by step photos for making your own brooch can be found on my blog. You will have fun going through your junk mail and old circulars. They contain all kinds of images that you can use to make a brooch of your own design.
If you would like to own this brooch, it is available in my Etsy Store.