I'm guessing they split up, DJ kept an eye on his kid while he did his thing. They're all good looking people, he is a celebrity that probably gets noticed by lifters quite often, and guys are all over her, and female can't help but notice him... every bro in the club wants to shake his hand and ask for benching advice lol.
There are PLENTY of pro BBers to make fun of, and laugh at, and point out their odd ways. IMO, this isn't one of the... If it was DJ and a son, for example, nobody would blink twice, right?
DJ and his daughter both dressed for a night in Vegas, that's a huge event. They're probably a few drinks in, probably quite happy and having fun. I think more dads should spend time with their adult kids like this.