A quiet workbench for the artifacts a browser session can make. Hand a screenshot back to the page, open a harmless file, then let the tour replay itself. Everything stays in this tab.
Choose the screenshot made earlier in the tour. The page will develop it here.
Give the page a small text file. It will show the receipt and a safe local preview.
Drop the animated capture anywhere inside the frame. The workbench will light it up without sending it anywhere.
This room has no upload endpoint. FileReader creates each preview in memory, and a refresh clears the workbench.