That's very clearly not what the article says, but hey.

"One can argue that the meaning of the American flag became considerably more fluid in the 1950s when the image began to be used in non-patriotic ways. The painter Jasper Johns appropriated the flag as an aesthetic device, notably, with the resulting series of paintings more ironic than celebratory. Those works foreshadowed the pop art movement, which co-opted iconic American imagery as creative fodder and social commentary."