Under what conditions do pop culture images and icons hold a liberating function? The important condition for me is the presence of alternative political culture that can provide the matrix of a liberating cultural movement for the pop culture representation. Pop culture images without a "pull from the streets" are easily swept up into the mainstream and rendered toothless in the face of oppression.
Ian H. Angus and Sut Jhally have argued in their book Cultural Politics in Contemporary America that this is the difference between a 1960s/70s John Lennon, whose music brought some political persecution because it was part of an alternative political culture, and a 1980s Bruce Springsteen, whose often liberating music criticized the vacuousness of the American Dream but yet, without an alternative political culture, was easily susceptible to co-optation by jingoistic patriotism. Forming alternative political culture in relation to pop culture can be a way to resist the co-optation that we would thereby risk.
This is why it is unfortunate that those of us in alternative political culture of various kinds rarely risk "dancing" to popular culture, "working" it. Without forging links between our movements and pop cultural icons, we often ourselves fuel the non-liberating beat of today's mainstream pop culture.