Speaker View and Gallery View

When there are 3 or more participants in a meeting, and no one is screen sharing, the View button will be displayed when you move your mouse over the Zoom meeting desktop.

See Changing the video layout (Speaker view and Gallery view) in the Zoom Help Center.

Speaker View 

Displays a large image of the person currently speaking, and places a yellow frame around their thumbnail.

Gallery View

Displays a thumbnail image of each meeting participants in a grid pattern. The size of the image varies depending on the number of attendees. The person currently speaking will have a yellow frame around their thumbnail.