Hmmm...they all co-ordinate? If you sewed 5 of the 6x2 inch strips together, you would get 7 1/2 inches. Then, if you put another strip perpendicular to it, to finish the 7 1/2 inch striped block, you would need a corner stone. Anything like a bunch of 2x2 inch squares around? Maybe the person was waiting to find that particular fabric.
Oops, just checked my math, doing the above would give an 8x6 inch block. Verrrrry interesting!