Yes I've just discovered this having tried unsuccessfully to pull it out with a suction cup. Fortunately I have since spoken to a recognised Apple repairer who told me that, because mid 2014 iMacs (A1418), are integrated screens unlike those on earlier models which are retained by magnets, they have to be replaced at a cost of around £700 in UK.Starting at a certain point, the iMac glass was being glued to the display panel and trying to remove that safely is something people have tried and failed. Thus the full display replacement.
I had sold mine but the buyer complained that there was 'dust under the screen'. Unfortunately I think since its return it is more likely that it is pixel failure and I am wondering if he or the carrier dropped it as I can't remember this being a problem before I shipped it.