To see content beside Glean, pin windows to the sides of the screen as shown here.

Right-click on a tab. Select "Move tab to new window".

Press the Windows Key and the right arrow key.

The window will be pinned to the right.

Select the other window.

Press the Windows Key and the left arrow key.

Drag the side of the windows to resize.

Prepare for recording.

Select the window to be captured.

Select "Share audio".

Select "Share".

Select the screenshot button.

The screenshots will be matched to the audio.