WWDC 2016 230 - How to display image on Voip Call screen?

In WWDC 2016 Session 230 (https://wwdctogether.com/wwdc2016/230) they show the incoming Voip call screen (at time 02.59) with an image covering the entire call screen. How is that achieved?

Got it - use a CXHandle with a phone number and add a contact with that number

WWDC 2016 230 - How to display image on Voip Call screen?
 
 
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