How does Google Meet allow you to screen share from another tab?

Question

In Google Meet, if you click "Present Now" then "A Chrome Tab", it brings up a window that lets you share from another tab. This is different to the standard

Answer 1

Google Meet uses the older extension API for screensharing. This API allows restricting the source types. It is still available but requires an extension (Google meet delivers a preinstalled extensions).

The standard getDisplayMedia does not allow restricting the types of displaySurface.