The TDC window works as illustrated, but once you get the hang of it kick starting is simple. Press the kick starter until you feel TDC -it will block your foot, that's why there is a decompression lever. Use that to get slightly past the blocked point of TDC and return the kick starter to the top and press down with the decompression released of course.
The TDC window is a useful training tool but soon enough it gets dirty and staring down at your kneecap prior to starting gets to be a pain.
As you can see fear of the kick start is also a useful anti theft device should these lovely anachronisms suddenly become desired by the rich and famous thus creating a trend...