What is your model Apple TV box?
Identify your Apple TV model - Apple Support
Find your Apple TV model number - Apple Support
The so-called “Conference Room Display” screen would show AirPlay information. On modern models, this would be overlayed over the screen saver, or a custom image. Conference Room Display has an on-off setting.
You should be able to get out of this screen, by pressing Menu or < Back on the remote. This could optionally be locked with a PIN code, or could optionally be blocked through a loaded device profile.
Use Apple TV as a conference room display - Apple Support
Settings﹥AirPlay and HomeKit﹥Conference Room Display﹥Conference Room Display﹥On|Off
