I am not a JetBlue flyer. In what sense is this a JetBlue lounge?
None.
It just happens to be in the JetBlue terminal at JFK, but mostly for the Aer Lingus flights which also operate there.
It is a nice space inside. And the food I tried was pretty good, too. Given that I get "free" access with my AmEx I'll likely use it when flying on JetBlue. Not that it will make me fly JetBlue more, but I will use it when there. I've got a
bunch more photos of it here.