Google Photos is preparing a new "Cinematic Moment" feature
Google Photos seems to be working on a new feature that will automatically create a "Cinematic Moment" in the app. This feature is similar to the Cinematic Photos feature, which allows you to create 3D versions of flat images. However, the "Cinematic Moment" is focused on videos.
Here's What We Know
The information was obtained from the APK parsing done by the Assemble Debug coder. APK parsing basically means looking at the code available in current versions of a given app and predicting features that are still in development. Mention of the new feature was found in the Google Photos 6.84.0.634885033 version of the app.
The feature will supposedly apply a slow motion effect to a portion of the video and create a "Cinematic Moment" out of it. This will be an automatic process, unlike Cinematic Photos. It's also possible that Google will include a feature that allows you to manually create "Cinematic Moments" in the future.
Of course, as with any feature that isn't official yet, it's not 100% certain that it will be implemented and when it will be. But the mention of this feature in the code gives a high chance of the feature coming in the future.
Source: Android Authority