Can't see the pic very well (too small) and although I've actually never competed, when I see a bodybuilder with stats of 5'9" and only 115 lbs, first thing that comes to my mind is "way too thin".
I am a natural bodybuilder (as in never in my life used AS) and you said you wanted a comparison so here it is:
I'm currently 5'5" at 140 lbs, 16% bodyfat (been as low as 15%) and have been training for 3 years as well. And I've been told I look like an offseason bodybuilder. I can't even remember when I only weighed 115 lbs! I weighed between 118-120 lbs when I graduated from HS, that's the lowest I can remember weighing, and I'm 4 inches shorter!