The Vonage Video API provides pre-defined layouts for broadcasting multi-party video sessions, including bestFit, Picture-in-Picture (pip), Vertical Presentation, and Horizontal Presentation. These layouts can be specified when starting a broadcast or changed during a live streaming broadcast using the OpenTok server SDKs or REST API endpoint. Custom layouts can also be created by sending custom as the type and a stylesheet property with CSS. The layout for a broadcast is created in a virtual DOM with a specific structure, and styles can be applied to streams using class selectors or pseudo-class selectors. The Experience Composer allows capturing the layout of a video call, including full web application elements, and broadcasting them.