In short, this Canon SELPHY ES3 is the SELPHY ES30 with a built-memory that can store up to 999 images. It helps you to easily do sorting which photos or images you want to print without need your camera or smartphone connected to the printer.
Of course, as a built-in memory is included into, Canon SELPHY ES3 mobile printer costs you $50 more expensive compared to the SELPHY ES30. The price tag of the ES3 is $199.99. Do I need to tell you again about Wi-Fi, Bluetooth, USB port, and so on?