Final answer:
The Comcast Building in Manhattan, formerly known as the RCA Building, is better known as 30 Rockefeller Plaza or Rockefeller Center.
Step-by-step explanation:
The famous photo 'Lunch atop a Skyscraper' was taken on the 69th floor of what is now known as the Comcast Building in Manhattan. Originally called the RCA Building, it is also commonly referred to as 30 Rockefeller Plaza or simply Rockefeller Center.