Lesson II. The vanishing window
Effect.The interviewer watches the shared screen. It shows the editor and nothing else.
Method.The assistant's window sets one Windows display-affinity flag, WDA_EXCLUDEFROMCAPTURE, and is left out of every screen share and recording.
The tell.The desktop app checks every window for that flag and names the one that's hiding. The browser version can't see it, so use the desktop app when you can.