I'd say just, "the new phone takes candid pictures" or "the camera in the new phone takes candid pictures". Or "a feature of the new phone is that it takes candid pictures." "Camera shy" means "doesn't like to have his picture taken". To take a picture is to use the camera. To have your picture taken us to be the subject of the picture. Candid can mean the same in both cases, but often it means just "not posed" in the second case (a "posed" photo is one where the photographer positions the subjects as he wishes.)