agent SHOULD provide a way for users to manually close the Picture-in-Picture

window.

The Picture-in-Picture window visibility MUST NOT be taken into account by the

user agent to determine if the <a>system visibility state</a> of a

<a for="/">traversable navigable</a> has changed.

The Picture-in-Picture window visibility MUST NOT be taken into account by the user agent to

determine if the <a>system visibility state</a> of a <a for="/">traversable navigable</a> has

changed.

## One Picture-in-Picture window ## {#one-pip-window}

<a>Picture-in-Picture window</a> associated with {{pictureInPictureElement}} if

the |state| is `opened`. Otherwise, it MUST return 0.

When the size of the <a>Picture-in-Picture window</a> associated with

{{pictureInPictureElement}} changes, the user agent MUST <a>queue a task</a> to

<a>fire an event</a> named {{resize}} at {{pictureInPictureElement}}.

When the size of a <a>Picture-in-Picture window</a> |pipWindow| changes, the user agent MUST

<a>queue a task</a> to <a>fire an event</a> named {{resize}} at |pipWindow|.

## Event types ## {#event-types}