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
Facebook Messenger to Launch on Mac Later This Year
A screenshot of the Windows version of the app reveals that it will look rather similar to both Skype and Apple's own Messages app on Mac. Facebook said Messenger Desktop will have many of the same features as the mobile version of the app, including support for group video calls and collaboration.
Facebook is expected to unveil the desktop app alongside several other new Messenger features at its F8 keynote today at 10:00 a.m. Pacific Time.
Update: Facebook's blog post has been republished after Messenger Desktop was unveiled at F8 as expected.
CNET has a video of the announcement: