Of the two, the first one would work better. It has a wider "spread" between the design pattern. The second one is too over-all and wouldn't have any difference in the blocks.
When I'm checking for this, I use 2 small pocket mirrors, that I join with tape to form a right angle; hold it on the fabric and then move it around to see if any neat designs form.
When I teach this, I encourage my students not to buy fabric until we've tested it out this way. Since you're buying this on-line? that's not an option.