While sneaking around in the school (after leaving the dorms and meeting up with Chloe), you will perform some tasks to gain access to the back room (Principal's office). Once Max and Chloe are both in the room and Chloe is seated at the desk, walk up to the desk facing Chloe. Angle the camera so that the bronze hawk is also in the scene with Chloe. If done correctly, you will see the option to press square and take a picture.
Any of the "optional photo" trophies can be easily obtained after finishing the episode by
using chapter select and playing again in photo mode.