I don’t know how you could have put a picture on you Apple TV, I didn’t think it has ever been possible?
when you power on the aTV (or do a reboot), you get a black screen with the apple logo for a moment, then it goes right to your home screen. If you're seeing something else here, you've jailbroken or done something outside of normal operation.
The application that's open when you put your aTV to sleep will be there when you wake it up. So if you're looking at a picture and leave it up when you turn the aTV off, the picture will be there when you turn in it back on. So if you don't want to see it, make sure you exit out before you put it to sleep.
Here’s the picture of a Warthog from my 2019 safari. I never put it on and can’t get it off or changed. I even deleted from my photos,and disconnected/deselected photos also. After 5 minutes the standard ariel view screensaver comes on which is fine.I don’t know how you could have put a picture on you Apple TV, I didn’t think it has ever been possible?
Oh my goodness thanks. Turning off conference display did it! It was so annoying and a difficult issue to look up on the internet because all the answers are about background. I need to remember to always come ask here!OH!
the airplay info is the important part here,
it's not what's on the airplay linked device.
on your appleTV, settings app -> airplay -> turn off conference room display
If you wanted, you can also change the image displayed.
you loose no features by turning it off. All it does is display that screen so people can connect easier.