The latest versions of Zoom for iPhone allow you to minimize a Zoom Meeting, yet maintain the Zoom video call in a picture-in-picture mode window.
This is super handy if you host or join Zoom Meetings from your iPhone, and want to continue to participate in the meeting while doing other stuff on your iPhone, like finding a relevant document, sending people an email, jotting down notes, or anything else that involves multitasking while on a Zoom call.
For the less familiar, Picture-in-Picture Mode allows you to place a hovering video window over the Home Screen and other apps on the iPhone, and it works with many third party apps, including now Zoom.