There's a pretty quick way to lose an audience. And that's with mindless wandering. Many of us introverts have a habit of moving while we pull our thoughts into view, looking at nothing in particular in the room while searching the dark recesses of our brains. Extroverts are full of energy - for them movement is large, fast and continual.
For a short time, either of these things is okay. It's an interesting view, from the audience's perspective. But make it a part of your routine, and it gets monotonous.
Try dropping an anchor - you pull the audience right in.