It is basically one of the emblems of pop art/culture in the 60s.
Warhol would paint things and people that defined American culture - from Marilyn Monroe or John Lennon, to a bottle of Coca-Cola.
"What's great about this country is that America started the tradition where the richest consumers buy essentially the same things as the poorest. You can be watching TV and see Coca-Cola, and you know that the President drinks Coke, Liz Taylor drinks Coke, and just think, you can drink Coke, too.
A Coke is a Coke and no amount of money can get you a better Coke than the one the bum on the corner is drinking. All the Cokes are the same and all the Cokes are good. Liz Taylor knows it, the President knows it, the bum knows it, and you know it."
– The Philosophy of Andy Warhol: (From A to B and Back Again), 1975
It was interesting to see that exhibit in South Korea, in the middle of a buddhist/gift shops area.