While it's true that most of us don't require professional photo processing for our visas and passports, some of us do need it. If your passport is not accepted for entry to a country that requires an American Visa, you will need an adapter or "chainlink" to get across the border. Or perhaps you're flying into Mexico and want your photo taken there - in which case you would want a" Grounds of Entry" card that states specifically that countries accept American Visa for entry.