North Korean leader Kim Jong Un, left, and South Korean President Moon Jae-in watch a magic performance during a banquet at the border village of Panmunjom on April 27. (Korea Summit Press Pool/AP)

What’s so funny? And why is Moon Jae-in holding a $100 bill?

There were many memorable images that emerged from the historic summit between the South Korean president and the North Korean leader on Friday. But one of the most surprising is one (above) that shows the two Korean leaders clearly having the times of their lives, Kim with his finger raised in the air and Moon holding a Benjamin.

It turns out a South Korean magician was invited to the banquet dinner at the end of Friday’s summit, an occasion in which everyone was feeling jolly after forging a joint declaration that included the word “denuclearization.” Sure, it was vague and there are lot of details to be worked out, but it’s a welcome relief from the talk of military strikes only a few months ago.

During the dinner proceedings — when Kim apparently stepped out to smoke only once but drank everything that was put in front of him — a magician came in to break the ice and get everyone laughing.

The magician (his name has not been revealed) went around the room of guests and asked one of the South Koreans for some money. The South Korean official pulled out a 50,000 won bill — worth about $50 — and gave it to the magician, who then promptly turned it into a $1 note.

Over the course of the next few tricks, he turned it into a $10 note and then a $100 note, which he then handed to Moon, the South Korean president, the Hankyoreh newspaper reported, based on accounts from multiple attendees. There were no reporters in the room at the time, just official photographers, so the events had to be pieced together from people in the room.

One South Korean at the banquet yelled out, laughing: “No more exports necessary from North Korea. You can create money just like that with magic!” That part of the story came from Park Jie-won of the Democratic Peace Party.

Perhaps that was the remark that caused Kim to raise his finger and smile.

There were card tricks, too. Exactly what the trick involved, we don’t know. But at one stage, the magician went to Kim Yong Chol, the former North Korean intelligence chief who is now in charge of relations with the South and who, incidentally, is under U.S. sanctions for his involvement in North Korea’s nuclear program.

But we do know that it resulted in Kim Yong Chol holding the trump card. And yes, the Korean for “trump card” is “trump card” — so the pun works in both languages.

This apparently caused much mirth at the table.

That could have been fueled, in part at least, by alcohol.

The booze put on for the banquet including Moonbaesul, a super premium brand of soju, Korea’s beloved rice liquor, with an alcohol content of 40 percent, and Myunchun tu-gyun, a wine with “notes of azalea petals and glutinous rice,” according to the promotional material.

Kim Jong Un “did not once refuse” the liquor during the almost-three-hour-long dinner banquet, according to participants who spoke to local media. “Kim Jong Un happily accepted every offer for drink and drank each glass bottom up,” one told the Dong-a Ilbo, using the Korean phrase for drinking a glass in one gulp.

But the North Korean leader, who was reportedly chastised for smoking too much by his wife during a dinner in Pyongyang last month held as part of a meeting to arrange Friday’s summit, only sneaked out for one cigarette during the banquet.

He went out to smoke at about 8 p.m. at an ashtray that the South Korean organizers had set up for him. That was the only time Kim was spotted smoking during the day of the summit.

“We heard that Kim Jong Un had been a heavy smoker,” the Korea Herald reported, citing an official from the presidential office. “But we could see him refrain from smoking in public, considering the symbolism of the inter-Korean summit and the number of South Korean and North Korean officials at the scene.”

Hopefully no one had hangovers on Saturday.

Min Joo Kim in Seoul contributed to this report.