This is the first I heard of "Vista" being used for something other than a Microsoft Windows program. A "vista" is actually the name of a geographical landmark, or rather that of a view of a landmark.
Further Explanation/Definition of Vista
It is a view often seen through a narrow avenue or passage. One example would be a row of trees, while another may be a long scenic passageway between two rock formations, with water stretching between. You can search dictionary.com for a more specific definition as not all vistas are necessary geographically-oriented.
Some vistas are actually actually views of the first sentence of this very paragraph "a view seen through a narrow avenue or passage." Some people would even take to mean a perspective view down the street with houses on both sides. It depends on the point of view.
The word "vista" that I currently refer to is the best vistas of the world (breathtaking vista views in nature), according to Bing Travel: