At the beginning of each fall semester in my introductory conducting course, we spend some time exploring and discussing what the act of conducting is--what it's about, how that's accomplished--in a fundamental sense. This involves several components like critical/comparative listening, body awareness exercises, expressive movement improvisation, and watching video.
I use video examples to show how conducting can be a whole-body, expressive act in collaboration with an ensemble of musicians, and that really exciting music-making can be the result (and that this idea is a fairly recent evolution of the conductor's role, as historical footage we view clearly demonstrates).
Two of my favorite examples each year continue to be Carlos Kleiber and Simon Rattle. Both are conductors with tremendous energy and charisma, who use their whole bodies extremely vividly and acheive remarkable engagement with their ensembles.