javascript - 什么是浏览器屏幕捕获 API 中的逻辑显示表面？

Question

我想知道逻辑显示表面实际上是什么？

在 MDN 文档中：
A logical display surface is one which is in part or completely obscured, either by being overlapped by another object to some extent, or by being entirely hidden or offscreen. How these are handled by the Screen Capture API varies. Generally, the browser will provide an image which obscures the hidden portion of the logical display surface in some way, such as by blurring or replacing with a color or pattern. This is done for security reasons, as the content that cannot be seen by the user may contain data which they do not want to share.

但是当我添加logicalSurface: true到视频常量中时，没有任何改变。当我将其设置为 时logicalSurface: false，也没有任何变化。每个人都可以给我一个真实的例子吗？

const constraints = {
    video: {
                logicalSurface: true // True and False are same :'(
    },
    audio: true
}
const stream = await navigator.mediaDevices.getDisplayMedia(constraints);
localVideo.srcObject = stream;

谢谢你。