Not to freak you out, but it MIGHT be the onset of male pattern baldness. The only reason I think of this is because of the miniaturized hair along the hairline. But do not worry, today's treatments are very effective and considering your hair (around NW1.5 in my opinion), you might be able to keep it for your entire life.
OR, it might just be a mature hairline. I'd recommend for you to wait for other members to respond before you hop into conclusion.
How old are you?
Also, do you have any hair loss in your family? Dad, mother's dad, brothers, etc?