At any given time while playing the game, you can stop and take a picture with your Phone. To access your camera while you are journeying through the cities of Kamurocho or Onomichi with Kiryu, all you must do is press up on the D-Pad of the Dualshock 4. By doing this, the first-person view of the Smartphone's camera will come up. In order to view the photos stored to your phone, you will first have to bring up the Pause Menu by clicking on the Options Button found on your Dualshock 4. From here, you will see the Photo Options in the bottom left corner.
While you have your camera on, you will still be able to freely move about in order to take the perfect picture. Should you press on the Options Button while in Camera Mode, you will instantly bring up your photo library. If you click on the left or right triggers, you can zoom in or zoom out for the photo you are trying to take. And if you press the Square Button, you will be able to cycle through the various filters, three in all, to add to your photo.
In order to take a selfie, you will need to press the Triangle Button while in Camera Mode. This will immediately flip the camera around entirely, focusing it straight on Kiryu, the Dragon of Dojima, himself. Even though both pictures and selfies don't provide much for players outside of extra amusement during their adventure, it's still a nice way to catalog Kiryu's final chapter along the way.