Sentence:  But she changed her <WSD>screensaver</WSD>, which was a photo of Julian eating scrambled eggs—he was smiling, holding his fork away from himself, as if he were waving the eggs at her—and replaced it with a photo of Olivia, looking up from her desk ... 
Meaning of the word marked with <WSD> tags:  The background picture of a computer, smartphone, or similar mobile device.