Then, from the building's rotunda entrance, a fully uniformed Boston Celtic bounds toward the street. He needs something from the bus.
It's Carsen Edwards, the No. 33 overall pick in June's draft. He's one of 41 NBA newbies who have come to the Panini NBA Rookie Photo Shoot to be photographed -- by themselves and with their teammates -- for trading cards and marketing materials. Their official NBA shots will be used by their teams and the league throughout their careers.
But before the regimen begins, there's time for some fun. Just walk past the room with the ball pit, within which you'll find a submerged KZ Okpala, a second-round pick who signed with the Heat. Then enter the main gym, where the rooks will pose in front of a word-salad backdrop of faux graffiti and face red-carpet-style questions.
ESPN caught up with several of them between poses to discuss a variety of subjects.
Tell us about the first time you dunked.
New Orleans Pelicans forward Zion Williamson (No. 1 overall selection): "The first time you dunk is always lit! I was 14, in ninth grade. I'm thinking, 'Man, I just dunked.' And even though I barely got it, the first thing I'm thinking is, 'I'm about to dunk on people now.'"
New York Knicks guard-forward RJ Barrett (No. 3 overall pick): "I could never dunk. Then, in a game, when I was 13, I just got a steal -- everybody was there, my parents were in the crowd -- and I just went for it and got it. I was one of the only guys who could dunk at the time, so I just felt great about myself."
Chicago Bulls guard Coby White (No. 7 overall pick): "You want me to tell you everything? Well, I was at Greenfield School, in the gym at my high school [in Wilson, North Carolina], and we just got done playing pickup. There was no air conditioning. This was when I was a freshman. I never really tried before. It was a rim-grazer, but it was good for me. It was an amazing surprise because I didn't think I was going to do it."
Denver Nuggets center Bol Bol (No. 44 overall pick by the Miami Heat, traded to the Nuggets): "I think I was in sixth grade. We were at an AAU tournament, and all the older players were dunking, and I was 6-[foot]-4 at the time. I tried to dunk. It took me three times. It was pretty cool because I didn't know I could dunk."
Philadelphia 76ers guard-forward Matisse Thybulle (No. 20 overall pick by the Celtics, traded to the Sixers): "Summer of eighth grade. It was in a park on one of those chain-link nets. My friends will tell you that the rim was bent down, but it wasn't. It was like, 'Did I really just do that?' I was really trying to wrap my mind around it."
Knicks forward Ignas Brazdeikis (No. 47 overall pick by the Sacramento Kings, traded to the Knicks): "It was in my driveway. It wasn't actually 10 feet, but that was the first time I was really like, 'Oh, I just dunked a basketball.' I think it was in eighth grade. It was indescribable."
Speaking of dunks, Vince Carter, as a member of the Raptors, won a legendary dunk contest in February 2000. He's now entering his NBA-record 22nd season, which he said will be his last.
Barrett: "I wasn't even born yet [Barrett was born on June 14, 2000, in Toronto]. That's absolutely crazy. I've had the great fortune to meet him, and he's a great guy. I'll take some of his tips on how to stay in the league for 22 years. He meant a lot for the generation [of Canadians] above me."
Williamson: "I wasn't even a thought [his birthday was July 6, 2000]. I got a lot of respect for him. I'll probably try to get some advice out of him if he wants to give it to me. But yeah, it's going to be crazy. Everybody knows about that 2000 dunk contest and what he has done for the game. So it'll be like, 'Wow, I wasn't even born yet.'"
Atlanta Hawks forward De'Andre Hunter (No. 4 overall pick by the Lakers, traded to the Hawks): "I was 2 years old. It'll be crazy. I'll be on his team. He has been playing basketball for my whole life [the day after Hunter was born, Carter scored 11 points in North Carolina's win over Louisville], which is wild. He definitely has a lot of knowledge and knows the game. Just being with a vet like that, you can't ask for anything better than that."
Boston Celtics forward Grant Williams (No. 22 overall pick): "In 2000, I turned 2 years old [on Nov. 30]. Hopefully, I get to meet him and have a conversation. I've heard he's an amazing guy. Just to pick his brain about how he stayed in the league so long -- that's something that I want to be able to do."
With whom would you most like to swap jerseys?
New Orleans Pelicans forward Jaxson Hayes (No. 8 overall pick by the Hawks, traded to the Pelicans): "It'd definitely beLeBron [James]. I'm a kid from Ohio. He's my all-time favorite."
Bol Bol: "Kevin Durant. He's my favorite player right now. I just love how he changed the game. He's a 7-footer and he's able to play like a guard."
Minnesota Timberwolves guard Jarrett Culver (No. 6 overall pick by the Phoenix Suns, traded to Timberwolves): "My former teammate Zhaire Smith [of the 76ers]. Just coming from Texas Tech, both getting to the league. He's one of my best friends. Having that dream come true for us. It'd be an honor just to swap jerseys."
Williams: "Kawhi Leonard and Draymond Green. My favorite player growing up was Kawhi. He's not going to be a favorite when we play him, but I would appreciate swapping jerseys with him. But he's also the type of guy who worked his way up. He wasn't the best player when he first got into the league, but he grinded and put the time in to become the player that he is today."
Which player are you looking forward to facing?
White: "Probably Damian Lillard. He's my favorite player. He has worked for everything he has had. He has earned everything and he's such a bucket. He plays the point-guard position well and is one of the best point guards in the league. Definitely looking forward to taking on that challenge."
Hunter: "I'm looking forward to playing against KD. He was one of my favorite players growing up. I like him as a player. Hopefully, one day I'll be at his level. I just really respect his game and really admire what he does."
Culver: "Jamal Crawford [who is currently unsigned]. I just respect him a lot. That's one of my favorite players. So it would be huge for me."
Cam Reddish(No. 10 overall by the Hawks): "Growing up, I was a big Kevin Durant fan, so I look forward to that matchup. He's just tough. He's got height and to do what he does ..."
What's your biggest fear or concern entering this new chapter of your life?
White: "My free time. You have so much downtime. You're always on a schedule in college. You always have people telling you where to go and where to be. So I think I'm going to learn piano or something like that."
Hunter: "I don't really have a fear. Obviously, the schedule is a lot different. That's the only thing. Just taking care of my body and being able to play night in and night out."
Thybulle: "You don't get to be a normal person anymore. You don't get to casually go to the grocery store and go unnoticed anywhere."
Williamson: "My worst fear is -- and I know it's not going to happen -- you hear about people losing their love for the game. I hope that never happens to me because I love the game so much. If that happens to me, I'd be so hurt."
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