Looks to me like you might be on the thin side. It's definitely not fat and stocky, and in relation to your hand it looks like about average to me.
But there's definitely nothing wrong with average. An average sized tool has served me very well for many years. (I might be envious of many of the guys around here, but then again, not too many people see my dick and the one who does regularly see it is very happy with it, so who the f--- cares???)