[blinks]

> Complaining that every attendee's attention is not > permanently fixed upon you strikes me as particularly vain.

I read this differently: an audience can get the most out of a presentation by paying attention.

If you're consciously communicating while attending a presentation, you're probably not getting anything out of what's being immediately said. In an information-dense presentation, that means you're not getting the most out of the presentation: unfortunate at best, and making the rest of the presentation hard to understand at worst.

Perhaps it's more useful read as an "attendee tip" than a "presenter request?"