Maintenance Menus in the AD5M

I watched a Russian YouTube video where he was able to get some additional maintenance screens.

All you have to do is start your printer and after it initialises, press the "i" to open the "Machine Info" screen. Once there press and hold the words "Machine Info" on the screen for about 7 to 8 seconds and then the maintenance screens will appear. Following are the screens:

Debug

Manual

Test

Shaper

Additional item on Info Screen

Level Sensor Screen

Can someone with knowledge about this please provide some explanation?

Thanks