Night mode is an automatic setting which takes advantage of the new wide-angle camera that's in the iPhone 11 and 11 Pro models. It's equipped with a larger sensor that is able to let in more light, allowing for brighter photos when the light is low.
macOS Catalina Now Available
Revamped Apple Maps Now Available in Texas, Louisiana, and Southern Mississippi
The improvements first rolled out in Northern California in July 2018, followed by Hawaii and Southern California in November 2018, and Arizona, New Mexico, and the Las Vegas metropolitan area in April 2019.
Now, the updated data is available across Texas, Louisiana, and the southern half of Mississippi, as Apple continues its pattern of rolling out the updated maps in adjacent continental U.S. states. Zooming into these regions displays more details and greenery in Apple Maps across the iPhone, iPad, and Mac.
At WWDC 2019, Apple said the updated maps will roll out to the entire United States by the end of the year, followed by additional countries in 2020.
(Thanks, Trevor K. and Chet C.!)