Working views (because there are some of them 'space-F4' for the main Action, 'space-F6' for the Source node, 'space-F7' for the Analyzer) are similar to what you can find in the 3D app under the label Perpective view. (and I think Combustion had a working view back in the days)
It not keyframable, you can orbit around your scene, pan, track, zoom the way you want in this view without animating your real Action Camera.
There is a Reset button on the bottom left of the UI (near the views pop-up) that allows the reset in position and zoom of the current working view.
This Working camera view is not represented in the schematic, is not in the channel editor and doesn't have menu.
Here are some cases where it could be handy
- Orbit around your comp scene without affecting your keyframed or 3d tracked camera, to check the alignment, the depth at which the objects are, the cast shadows, position of lights, etc...
- Same thing but in Source Node space
- For the Analyzer one, it could be used again to orbit around the 3d points before converting them to Point Cloud objects, to see if the reconstructed scene makes sense (in terms of scale, camera position, position of your grid, etc...)
Note: Don't forget that the F7 hotkey is doing a cycle between 2D Analyzer view (only the 2d trackers are visible) -- 3D analyzer view (trackers and 3d points are seen through the eye of the reconstructed camera, the Left camera in case of Stereo Analyzer) - eventually 3D Analyzer Right view -- and back to 2D Analyzer view.