http://www.mccallsquilting.com/articles/Radiance
If those blocks finish at 4.5", then you want to PP.
It looks - and it's a bit hard to see - like there are 9 rounds -
that means each strip finishes at .5".
Log Cabin blocks have a tendency to go off kilter, and with the strips this small, it's even more likely. By PP, you're avoiding all the squaring up after each round (or strip) because the paper will guide the placement.
If you've never done PP, do a sample block to get the hang of it. But once you break it down, you can even chain piece it.
Looks like there are 16 blocks of each color.
You just need to be organized when at the machine.
Actually, I think a regular log cabin block is easier than the pineapple.