Small face measurements in Korea?

So, I came across a youtube video of the guys from Asian Boss measuring random womens faces off the street. It was to see if the women fitted into the Korean average face length. Now, where I get confused here, is that they appeared to be measuring the women from the top of their head, to their chin. Whereas, everywhere else online on videos, forums etc it says to measure the length of the face, you measure from hairline to chin. I measured my own face from hairline to chin after watching the video, and it was about 19cm. Like in the picture here of Go Ah Ra, they are measuring her from hairline to chin and it is also at 19cm. I measured a few friends and families faces hairline to chin, and they were all around the same measurements of 19-21cm. But when I measured my own head from top of the head to chin, and my friends/families from top of the head to chin like in the video, the measurement was MUCH larger than the 22.2cm like is suggested is the average in the video. So now im left wondering... Do I, my friends and family all just have ma-hooosive faces and heads? Or did these guys measure wrong and is the rest of the internet right by saying you measure hairline to chin to measure face size? His tape measures number 1 mark did seem to start lower than a normal tape measures would (can be seen if you pause the vid at 2.15). I thought maybe someone here would know, what is the correct way to measure face size in Korea? Also, what are your measurements from both hairline to chin, and then tip of your head to chin?

Thanks!