Dogs have a better sense of reality than humans. Dogs become ecstatic when they see their human owners in person, even if the human was only gone for a couple of hours. The longer the human is gone, the happier the dog will be when they are reunited. If you go on vacation for a week, the dog will become saddened while you are gone, then overjoyed when you return.

But—and this is key—if you call home via telephone and the dog hears your voice, it will get excited for a second until it realizes that was just the phone. When the dog knows you are not actually there in person it won’t care anymore. Dogs have no interest in listening to your disembodied electronic voice or seeing your face on an iPad—because that is not you. Dogs’ primary sense of perception is smell. If they can’t smell you, you’re not real.