Back in HeartGold & SoulSilver, there were various spots where you could have your photo taken. Pokémon X & Y brings this back with even more detail

Dotted around the Kalos region, at various notable landmarks, there are signs which all you to call up Phil the Photo Guy. When you do so, he will arrive with two options. First is to take a photo, and the other is to view photos that you have taken. This service is completely free, though you have the option to tip Phil after completion of the photo

When you're taking a photo, you can control the angle and position of the camera with the 3DS's gyroscope. Various other bits can be controlled through the touch screen. The A Button opens up more options

Zoom: The zoom is controlled via the circular slider in the bulk of the screen
Focus: There's a second slider which deals with the focus of the camera, allowing you to blur out everything you don't want, or to make it crystal clear
Natural Light: Using the Y button, you can control the light levels
Shutter Size: Using the X button, you can control how open the shutter is. This will shift the focus of the photo.

When you're ready, press the R button and the photo is taken. You can then save this photo onto the SD card on your Nintendo 3DS.