Vertical Flakes next to Boulders

I noticed a vertical flake next to a boulder. Just a moment earlier, I had discounted another flake next to a boulder:
Then as I walked around in that area (the woods behind the site described in the previous several posts) I saw other examples of vertical flakes next to boulders or large rocks.
This is the sort of thing which my friend from Carlisle is forever pointing out. It seemed genuinely significant here since it ocurred at least four times in a small area.