Last week, Apple released its first developer beta of macOS 10.12.1 Sierra, followed a day later by the public beta release.
Today, the company has made its second beta of macOS 10.12.1 available to developers, bumping the build number up to 16B2333a.
Unsurprisingly, given that this is an incremental update, this latest version of the OS focuses on bug fixes and other minor improvements, rather than major new features. The update does, however, include support in Photos for the new Portrait feature on the iPhone 7 Plus, which arrived with the iOS 10.1 beta last week.
Apple rolled out the first full public release of macOS Sierra a week ago, bringing a range of improvements and new features, including Siri support.
Source: Apple Developer