Other hints if you are still having trouble finding it:

1. Make sure the room is well lit.

2. Put your face right up to the poster and slowly move away

3. Make sure the poster is at eye-level.

 

Below is the image that is hidden in the "seeing things?" poster.

bottlekeysweb

 

Below is the image that is hidden in the "Distracted" poster.

no_cell_phone_steering_wheel