To unlock the trophy that's called "Anyone see that?", you must complete a predator encounter without the enemy seeing you from start to finish.
You can do this on the Final Offer's first predator room that you encounter. Go behind every guy that you see and perform a Silent Takedown. To perform a Silent Takedown, you must be standing behind an unaware enemy and then press
when prompted on the screen. Batman will slowly, but surely choke him out, rendering the guard unconscious.
Here's a video showing you how to get both this trophy and the Silent Knight trophy at one time. All credit goes to Powerpyx for playing the game, creating and then uploading it for everyone to see.
Good luck and have fun!