1) Connect iPad to Apple TV via Airplay. Select below link on a guide for connecting iPad to Apple TV via Airplay.
Connect iPad to Apple TV (AirPlay)
For best results, use landscape orientation of iPad so the iPad will show larger display on the TV.
2) Open the Camera app.
3) While the iPad is in the landscape orientation, place it on an iPad stand with the iPad camera pointing down. Below are examples of iPad stands provided by KIBSD.
4) When finished, select Stop Mirroring via Screen Mirroring menu.