You get this achievement during episode 1.
You'll wake up in the jungle, there's a woman nearby, you need to follow her, she'll lead you to Kate, once you meet Kate you have to talk to her, this will trigger the flashback.
Now you're in the flashback you need to use your camera to take a photo of Kate being handed a bottle of water by the hostess, now you need to examine these 3 objects;
• Magazine (to your left)
• Photos (to your left)
• Backpack (on the floor)
Once you've done this the achievement will unlock!
* Credit to 360VideoGuides for the video