Just catching up here... it seems you have a little bit of an issue with how you perceive your body. And that's common around here; we're all generally tougher on ourselves.
I just wanted to point out that you have a very proportional body right now. You even have the X shape meaning your legs and shoulders are your widest point with everything tapering in between. That's an awesome physique to start with at your age!
A lot of people talk bout the tapered V shape for upper body but it's even tougher to reverse the taper from your abdomen/waist to your legs. You have that going now and it's not easily achieved.
In regards to definition, I've noticed that some of the guys on here who are prepping for shows mention that leg training causes inflammation and it reduces the definition. They cut out all leg training leading up to a show so the inflammation goes away and they're left with the shredded, vain popping look that everyone loves.
Unless you're stepping on a stage in a speedo, don't worry about the definition too much. We can see the separation between the different quad muscles now and I think that's a good look to have day in and day out.