Presence, as in: an impressive appearance or bearing, is often established via the application of atemi during the execution of a technique. Atemi delivered in an indifferent manner or with the intention of missing the intended target will embolden my uke and serve to diminish my presence in his eyes. Part of my training is getting my partners to believe in the reality of my atemi, even while they know that I'm not going to apply the strike with force enough to do any damage.
Atemi delivered with correct feeling will result in uke feeling the energy of my intent long before the blow arrives. This, in turn, will adversely affect his positioning and balance thereby increasing my presence as perceived by him. When I deliver atemi during practice I make it known to my partner that, 'if you don't move I'm going to hit you', via the projection of my intent and by applying the blow accurately, on target.
(Original blog post may be found here