"Draw, Smile" uses your front-facing camera (or TrueDepth camera system if you have an iPhone X) to know when you are smiling, so it can save your masterful drawing to the Photos app on your device. No camera or facial data ever leaves your device, nor is it stored for more than a split second as "Draw, Smile" does its best to determine whether or not you're currently smiling. Thanks for using and hope you are enjoying your new interface!