Source: Google
While version 8.0 of the Google Camera app was initially just available for the Pixel 5, it seems Google is now ready to share its features with older Pixel devices. Version 8.1 of the app has started to roll out to devices as old as the Pixel 2 and 2 XL.
It's not a complete overhaul of the app, but some of its features have been redesigned or reshuffled. Older Pixels should see features like zoom shortcuts and Audio Zoom, which can reduce background noise. The Pixel 4 and 4 XL get access to the Pixel 5's Cinematic Pan video recording feature designed to produce smooth panning shots. The update is in the middle of its rollout, so you might have to wait a bit for it to come your way.
Source: The Verge