screensaver

noun2

1. •
   A computer program that displays aesthetic patterns or images when the computer is not being used, originally intended to prevent screenburn.

   • I configured my screensaver to appear after only two minutes, because I enjoyed watching it so much.
2. •
   (nonstandard) The background picture of a computer, smartphone, or similar mobile device.

   • While we waited for Zac to be taken into surgery, I thought of all of his suffering up to this point […] It brought to mind the screensaver that Zac, a few months earlier, had changed his Ipod to. — 2015