He likely did not. A user would create a scene page for the current 3D view (name it whatever.)
Then create the section cut, and using the move tool move it up above the porch at the level so it cuts the windows on the main floor.
Afterward create a new scene page for the plan view, name it “Plan” if you like.
Then do as Steve said by changing the camera view for the “Plan” scene page, and then update the scene.
Now you have two scenes each with it’s own camera settings. You can switch between the 2 scenes depending upon what you need to do, without upsetting the settings for either.