This is is easier than one would think. In fact, it's kind of a throwback to the achievement from the original Dead Rising game: Score over 10,000 PP in a single picture.
Okay, down to business: After you take your first dose of Zombrix and you venture out into the South Plaza, you'll see a lone woman in yellow fighting off zombies at the coffee stand. Talk to her and she'll agree to join up with you and find her wimpy husband. He's actually not too far from where you pick up the woman - in the one store at the right corner if you're facing the entrance to the Americana Casino. Find him, and the "happy" couple will embrace and two little PP icons will appear above them. Snap a pic when you see this, and you'll get over 10,000 PP for your trouble AND the achievement.
UPDATE: Thanks to EvilTrovis for correcting me - this achievement is one you get as you play. Just take really good pictures worth over 1000 PP if possible (Look for the PP icon over survivors or betetr yet your co-op partner) and you'll eventually get this achievement.