Most celebrity tend to attend the second day of concerts nowdays.
The Bruno Mars concert was sponsored by Hyndai Credit Cards, whose CEO Jung Taeyoung is the husband of a sister of the owner of Hyunda and Kia Motors, Chung Eui-sun. (Their surnames are both pronounced 'Jeong')
Chung Euisun, the owner of Hyundai and Kia Motors, attended the Bruno Mars concert, with some unidentified people, probably his bodyguards who get to attend because they serve the top honcho. Chung is the grandson of the Hyundai founder Chung Juyung.
And presumably he invited some VIPs in his circle to attend the event, but their names are not disclosed. It is likely that after the concert was over Mars would have a private party with the Hyundai and Kia Motors owner, his brother-in-law who organized this concert, and some people in the circle of the Hyundai and Kia Motors owner but of course we don't get to know much about such event.
More relevant to Kpop fans would be the list of entertainment figures who attended the Bruno Mars concert.
The people in this picture, in order of appearance
BlackPink - Jennie, Rose (Lisa went to see Minnie in the nearby Gidle concert)
Lee Jehoon, actor
Lim Youngwoong, trottist
These people are said to have attended it
Saturday
NCT - Mark, Haechan, Runjun, Chenle, Kino, Jaehyun
Winner - some members
Treasure - some members
the dancer Aiki
Sunday (Some of them are mentioned above)
BTS - Namjoon, Taehyung, Jungkook
Blackpink - Jennie, Rose
Lim Youngwoong
Actors Song Hyekyo, Park Sunghoon (one of the stars at The Glory)
Actors Lee Jehoon, Han Gain, Yeon Junghoon, Lee Donghwi, Ryu Junyeol
EXO - D.O.
Japanese actress Nagano Mei
Lesserafim - Sakura, Chaewon, Jennifer, Kazuha (don't know about Eunchae)
Jo Seho, an entertainment figure
The list is not exhaustive. I compiled it by looking at several sources, so i might have missed some.
When a country is conquered, all of its officials , generals, etc line up with their heads lowered, to present themselves to the Conqueror, putting themselves at the Conqueror's mercy.
All these people attending Bruno Mars concert to curry favor to him
(apparently Mars only talked to Bambam. Mars apparently remembered Bambam in a Baek Jongwon show and told Bambam that B worked hard.)
negates KPop's success up to this point and makes it look like June 18 , 2023, is the Waterloo of KPop.
(Of course, no one thought about inviting the Senior Singer there, in case someone is looking for my mention of the figure who contributed the most to destroy the Kpop Empire)