Picture 2 is showing the front and back of the trimmed block.
Picture 3 shows 4 identical blocks and how they will lay in each completed 5 1/2" block.
Picture 4 is the completed 5 1/2" block.
I should have also mentioned that I take the paper off the back of each little log cabin before I sew the 4 units together.....it makes it easier to sew the 4 together. I press the seams open when putting the 4 blocks together. It takes some of the bulk out of the center of the block.