They were young, but they were still heroes.
They had been trained by the best of the League, and could go toe to toe with them too. (It's happened; they all know that if push came to shove the League could be taken out by the kids they trained and outnumbered.)
One of them was already a member of the League - forgetting to tell them his real age of ten was one way to go about it - and another recently joined his mentor in the ranks of the heroes of Earth.
And as the rest of them look to the Hall and up toward where they know the Watchtower hovers they all know that someday they'll join the ranks as well.
Robin, Kid Flash, and Aqualad, the founders of the Team along with Superboy, stand proud with Miss Martian, Artemis, Zatanna, and Rocket - even if they are forced to remain in the shadows.
Someday they will step into the spotlight as new Justice League members, and hopefully new young heroes will be ready to take their places on the Young Justice team.