From The Guardian:
Hugh Bonneville and Gillian Anderson play the Mountbattens in Gurinder Chadha cheekily Downtonised but watchable version of history
While the US TV view of the UK is all Downtonised nostalgia, British telly is obsessed with documenting the extremities of America.
And from the Incorporated Council of Law Reporting:
It was almost as though the trial had never been won, and we’d been served a sanitised, Downtonised version instead.
I can't find a meaning in the usual sources. What does it mean?