What makes that important, is that, very often, the supposedly teen sidekicks of heroes are portrayed as just somewhat shorter adults. Take this cover from a somewhat recent issue of Robin:
Here you can see that the boy is pictured pretty much as an adult. Why is that important? Good question. I find myself as a reader much more impacted by the visual representation of children involved in the violence that the teen sidekicks of the major heroes of the DCU routinely wind up confronting. I'm much more shocked to see Batman (under mind control, though no one knew it at the time) physically attacking a Robin who looks like a little boy. Here, let me see if I can show you more clearly what I mean.
Here is a scene from the cover of Robin 170:
Now, here's some of Kerschl's work from Teen Titans: Year One:
Notice that both characters (though different boys--Tim Drake and Richard Grayson, respectively) are supposed to be roughly the same age. However, notice that one is drawn as a small adult, and the other is drawn much more clearly as a child. Both are injured, though one is far more injured than the other (lots more blood on Drake). And yet, as readers, we are much more inclined to feel sorry for the one that is obviously a child, rather than the one that is merely shown to us a somewhat small adult. We're hardwired to respond in such a way, and Kerschl is counting on this fact to drive his work home.
In other words, how we respond to visual representations of children and adolescents has to do with more than just knowing that they are visual representations of children and adolescents--there's something we as people are hardwired to look for, such as body proportions. And I've noticed that I am much more shocked by violence to a visual representation of a child.
So I've been tracking my reaction to the comic not just through the writing (which is way above average for the first three issues), but through Kerschl's obvious attempt to show us what teenagers in costume would look like in many ways. And I think this is important, because it makes us look closely at the idea of the teenage sidekick. The shock I experience seeing children in harm's way (and, in issue 1, even having to face off with their own mentors) is really interesting to me as I read this particular comic. I find I don't react the same way watching a character that I know is supposed to represent a child or adolescent, and yet they do not appear as one.
It's a really great comic on so many levels, but this one is the most striking to me.