It is very very simple to make, just as feline fanatic said. You make your 'six patch', which is rectangular in shape. The black strips on each side are wide enough to make the block become a square.
Ignoring the seam allowances, let's say you use 2" squares to make the six patch; the block would be 4"x6". Add a 1" strip to each 4" side so that the block is now 6" square.
Now you simply turn each block one half turn to create the quilt. It is sort of an optical illusion, because the viewer does not see that the blocks are actually square.
My quilt group just completed one that used large floral fabrics instead of a six patch in the center. It turned out beautiful. You can see it on my blog at
http://imkeepingbusy.blogspot.com/20...quilts-to.html