I was in Poughkeepsie last week and that’s a picture of my train ticket. “POKIPSE” is a pretty good phonetic spelling of the name, although I would have gone with POKIPSEE.
I’m curious as to why the name was shortened: “GRAND CENTRAL” is 13 characters and “POUGHKEEPSIE” is 12, so it appears that the name would have fit on the ticket unaltered. Maybe the MTA is trying to help people pronounce the name?