dark art of conducting?

I’ve always wondered why conductors do (or don’t do) certain things that seem either idiotic or genius-y in the heat of the moment. Then I read this paragraph in Michael Hovnanian’s blog – I think he’s hit the nail on the head:

The problem with making conductorial convulsions the source of all musical inspiration is that they are often vague. The other night, my stand partner asked what I thought about the Maestro ‘glaring’ at us during a certain passage. I thought he had been smiling at that point, and so had aimed my toothiest grin back in the direction of the podium. Needles [sic] to say, after the performance I departed the concert hall more quickly than usual, just in case. Paradoxically, much of a conductor’s strength comes from that vagueness, in that it binds the musicians more closely to him – the source of confusion simultaneously its only solution.