This may be obvious, but it wasn’t to me. If you are using an iPad at the office connected wirelessly to an Apple TV, go into the iPad’s Settings app and turn off Auto-Lock before the meeting begins. Otherwise, your iPad will fall asleep sending the AppleTV back to its default screen. Since you won’t be looking at the screen behind you, you won’t realize it. Then, when you are about to make a really important point, someone will raise their hand and ask if you could just shut up so they can watch Wall•E.