In America there is a turn of phrase which makes a play on a previous word to indicate mild - sometimes humorous - derision. So someone might say about breaking the speed limit 'Oh speeding, shmeeding'. The 'shm' sound is placed in front to give the sense of the previous word not being important or not being considered worthy of full attention. Pomo is the shorthand word used by some to indicate postmodernism.
Enough of preliminaries! This letter from America wants to say 'pomo - shmomo'. Recently I asked a suitably trendy professor of English at Yale University about postmodernism. He told me in no uncertain terms that postmodernism was passe. This caught me by surprise. Don't you read Derrida any more? I asked askance. Oh yes, he replied, maybe, but that's all out of date now. Hasn't been fashionable since the mid-90s. What's in now? I asked. Ethnicity, he said.
About which I'm still not quite sure what he means, other than that there is an apparent divergence in university syllabuses into lots of different subsets of subjects - like 'African American Literature' or 'Native American Art', etc.