Here's the thing...
The US uses the Imperial Measurement System. That means your US passport photos are measured in inches.
The rest of the planet uses the Metric System. That means THEIR passport photos are measured in millimeters.
If you're a citizen of a foreign country living in the US, and you're in need of updating your passport for your native country, you're going to need a passport photo that is measured in millimeters and sized to the specifications of your native country's passport photo requirements.
If you're from the UK, it'll be 35x45mm. If you're from Canada, it'll be 50x70mm. If you're from Greece, it's 40x60mm, and if you're in need of a Chinese Visa, it's 33x48mm.
Your local drugstore employee may not be aware of these differences and will give you a 2x2 inch (51x51mm) image, that will promptly be rejected by your consulate.
Do it right the first time and contact Central Florida's most experienced professional passport photography studio, Newsome's Studio of Photography, located at 10012 N. Dale Mabry Hwy, Suite 219, Tampa, FL 33618.
By appointment only, call 813-968-2810.