Nice job man.
The one quad shot has me believing his squat claims. Even if he’s not going ATG or to regulation depth it looks like his legs could move some decent mass. But really, who cares.
OP, at your age the best advice is to just stick with big, compound exercises and eat as healthy as you can. You’re 13! No need to over analyze this.
BTW, there’s another name for people at 3% body fat… a corpse! You are down in the single digits but nobody can maintain 3% for more than a week. Don’t forget, all your muscle tissue has fat in it. Again, it doesn’t matter. Just keep it simple and keep on progressing. Good Job!