What I see is that your squares are not square or the same size. It can be caused by cutting or stitching. Buy new blades for your rotary cutter and use it. You should be more accurate. That will take care of the cutting part. Measure from your needle to the outside of your foot to see if you are stitching a scant 1/4". If not, mark it (I use painters tape to mark that line across my machine. It helps in keeping even seams. The other problem that I see (having been there, done that) is the blocks don't line up across the lattice. When you start attaching the second block to the lattice, you need to draw a line on the lattice, so that you know where the points of the second block should line up with the first block. That's also true of the the narrow pieces of lattice. I sew mine so that the pieced blocks are up and I can see where I am sewing, that way I can sew thru the points the same way across the block. I would take the blocks off the lattice and resew it. It might not be perfect, but if the points lined up on the lattice, it wouldn't be so noticeable. Good luck. As I said, "Been there, done that".