Now that the photos.app is on mac, is super light weight and is highly integrated between the cloud and the mac and iPhone, Apple should have a "quick photo" button just like on iPhone, i should be able to select one of my most recent photos, that may have been synced from my iPhone or put into photos.app manually, or use my FaceTime camera on my mac or open a photo selector. This will emulate the iPhone ability quite nicely and work well with photos.app integration.