One of the highlights of NBC’s Olympics coverage has been images from the swimming “ready room” at the Aquatics Stadium in Rio de Janeiro.

It was there that we saw Michael Phelps angrily glare straight ahead as South African Chad le Clos bizarrely warmed up by shadow-boxing in front of him.

And it was there we saw American swimmer Lilly King’s reaction to Russia’s Yulia Efimova wagging her index finger after a semifinal race.

How did that inside view come about?

“I think it’s very rare in sports and certainly in television that you’re allowed in the locker room,” NBC Sports Group chairman Mark Lazarus said on a conference call with reporters Thursday.

“When you’re in the locker room, right as competition is about to start, I think it’s exciting. We’ve also seen a lot of really sort of fun athlete-to-athlete competition/game playing and playing head games with each other.

advertisement | advertise on newsday

“So in a voyeuristic society, when we can let people behind the curtain that way, I think it’s a very good and gets people excited. So now we’re doing it two ways. We had a camera back there that we were using on television, which was really a handheld camera, a cameraman back there showing it.

“And the reaction we received from viewers and from people was so positive that our digital team was able to get a permanent camera based in there. So we stream that live now all the time during the swimming competition as a second screen add-on.

“I think it’s two things: One, it shows how we’re reacting to things that consumers are interested in. Two, it shows the sort of breadth of our rights and our relationships with the International Olympic Committee and the Swimming Federation.

“On short notice we were able to get that kind of access and give fans something they’re really interested in.”