Throughout the game you will receive photos (usually from Catherine).There are certain photos that can only be obtained through specific actions or based on your karma. The earliest instance of this is Day 2 at the "Stray Sheep" when you receive a text from an unknown number(Catherine). Telling her that it's you will give you a picture of her lips.
Have pink Karma on Day 3 and Catherine will send you a picture of her in a towel.
On Day 6 or 5, Catherine will send you picture to make you feel better. It will be one of two things: Her in red leather and a whip or her in a nurse outfit. You get this one regardless and can change which one it is by going back to the text and hitting TRIANGLE (picture button)
On the last night at the stray sheep you will get a text from your wireless provider saying that their was recently a problem with their phone (missing pictures). Attached to that text is a picture of Katherine either of her next to a birthday cake or her in the bathtub.You can see both of these regardless, but if you have Pink karma you will get a bonus picture.