That one person who either a.) has to be in every photo or b.) Takes thousands of pictures during completely useless events. The Photo-Slut will do this because she needs to feel like she is the center of attention; or because she loves hugging and smiling with other guys and thinks the excuse of a picture covers up her "Photo-Sluttyness"
"Hey who the hell is this chick? She's taken like five pictures with me."
"I don't know man, it's just some ratchetPhoto-Slut