I also wondered what a goose poop quilt was. this is what I found online-
quote-
I took a class with Pat Speth (Nickel Quilts), and she calls those little left over half-square triangle units from making Flying Geese "Goose Poop" -- because it's what's left after the goose is gone.
[If you have geese around you, you can certainly understand that! OY!]= quote
So a goose poop quilt is made with what is left of when the goose block is done.