Hm. I'd disagree, I think when you have a video guiding you where to put which strands, you can follow that on either your or someone else's hair. But maybe that's just me, everyone's different :)
Take it from someone who couldn't figure out how to braid her own hair until she was 12: at least some of us watch these videos and we're like a clam trying to climb a tree. We lack spatial conceptualisation. However it's far easier to do it on someone else's hair based on a video that shows how to do it on oneself, than the other way around.
Imagine trying to braid someone's hair. easy, right?
Now imagine trying to braid your own hair, having never done it before. A video isn't going to help all that much
Now imagine trying to braid your own hair, having never done it before. A video isn't going to help all that much