Originally posted by Mares
I understand it to be a sign of respect for your Sensei and/or Sempai. I believe it is disrespectful and inappropriate to have your Sensei or Sempai look up at you. As kohai you should remain at the same level or below your Sensei, especially when being spoken to. Hence the need for shikko as well.
Hmm. Interesting idea. I'll have to look into that. I've heard it before, but never heard it really substantiated.
I do know that some of my teachers have been shorter than my own six-foot-plus and have had no problems with me standing as they taught.
On a practical note, getting down in seiza or anza (if we're playing high-formal in my dojo, we do iai-goshi) helps clear the line of sight so folks can see what's going on.
It's less a matter of respect than of practical classroom manners.