In late 2019, we told you that Google is testing the video zoom feature in the Google Photos app. And now it looks like it is ready for mass deployment.
The function works in the same way as you enlarge photos. This allows you to see small details in the videos, mainly if they are shot in high resolution.
Another innovation – double tap allows you to fill the video in full screen if there are black bars on the sides (as a rule, the video aspect ratio is 16: 9, and the aspect ratio of modern smartphones is 20: 9, which is why the stripes appear in video viewing time). Another double tap returns the standard display mode.
As usual, with such updates, they happen from the server-side. So if you haven’t got new features yet, don’t worry – they should arrive on your device soon.
Source: Android Police