It's funny, I was just thinking about how much I used to like to present carefully constructed talks. I'd throw in some jokes (very hard for me!) that seemed discursive (I'd look for an opportunity), but were not. Presentations are performances, or were for me at least. I'd work really hard on them. Teaching classes are one example. I'd work so hard on them! Mostly to make them look easy, like any good performance.
I agree, there's a performance element to presenting, even in a business environment like I mention above - it's a show really, a showcase I guess. I've seen some bad ones and some good ones and learned from them both. As I said in another comment, it's something one loses the knack of if it's not used.