Well first picture was taken in lower light conditions since the sun was already below horizon. Normal iPhone 6 Plus pictures are more noisy unless you use a long exposure.
Also, regular iPhone pics are nowhere near the detail of these ones since these are 12mp low noise pictures while regular picture from 6 plus are 8mp. That indoor picture of the dome would normally produce more noise when zooming in than it does here.
In fact, there is enough detail in the bottom picture that you can zoom in on the gazebo without loosing detail. Enough detail to crop and print.
Well....ok, but I was really asking the other guy about the "incredible" statement...
The term incredible is a pretty lofty statement to make about *any* photograph given how high the
true bar is in the world of photography. So even if the resultant images have somehow managed to break new technical ground within it's genre of cameras such as an iphone, to have the term incredible be relevant and not over-enthusaistic / misplaced, it would have to also be a simply amazing set of photographs based on mesmerizing content brilliantly seen and photographed in addition to those technical virtues.
These images being incredible from either a technical or a content standpoint.....?....not so much.