In macOS Catalina 10.15.5, Apple introduced a new Group FaceTime feature that disables the option that automatically enlarges the tile of the person who is speaking.

By default, ‌FaceTime‌ has a dynamic view with a tile for each person. The person who is speaking at the current time has a larger tile, while tiles for people who are not talking fade into the background. Apple refers to this as Automatic Prominence.

However, with people recently using group ‌FaceTime‌ chats more than ever before, Apple appears to have realized that this behavior is not a great experience, especially when a large number of people are on a call.

In macOS 10.15.5 and later, the feature can be turned off by following these simple steps.

1. Launch the FaceTime app on your Mac, from the Applications folder or the Dock.
   
   
2. Select FaceTime -> Preferences in the menu bar.
   
   
3. In the Settings tab, under Automatic Prominence, uncheck the box next to Speaking.

A grid with static image sizes for all call participants is likely to prove better for meetings and events where several people are talking at once or right after one another. It also mimics the layout options available in Zoom and other video chatting apps.