The last 3 pics are of the higher-density system , as follows: 3rd-last showing the back perimeter edge while the system is turned upside - down ..hopefully you can see the `thicker`hair [higher density] than in the ones above it which are of the more recent lighter-density one.
2nd- last is the nape area just sitting on my hand.
Last one shows the way the nape hair sits in against the skin....thicker-looking than in the shot up above which as I said, is the more recently-delivered system with a lighter density.