Unless you intentional shaved those hairs they wouldn't just grow shorter in a pattern like what we see in the pics you provide, something is causing your hair to do that, in this case it could only be Androgenetic Alopecia. Whilst the hairs appear to mostly still be terminal they aren't going to grow at the same rate as the hairs directly behind, if you were to compare under a microscope the diameter of the hairs in question with the hairs behind I have no doubt you would find that they are smaller. Those hairs are on a path, a few more HF cycles and they will no longer be visible anymore.