Joiner plays at a maturity level far above his age right now. He missed his 1st two shots which were good open looks but he didn't force things later on until he had to launch the "another zip code" 3.
He also seems to be the most vocal player on the team. I get the sense he really likes his teammates, he was constantly bringing them together to huddle up and calm the others down during dead ball periods.
Honestly, that aspect of his game is probably my favorite quality in him thus far. And I really like his defense.