You should turn on the blue light, then put the picture on the wall where it is marked, then look at the picture the whole time and go straight back (between the two flags) and that's how you get into the other room.
Unfortunately this puzzle really isn't that clear for people :( after the jam we will give more help with this room
You should hold the picture in your hand, simply look into the marked square and press E. (the crosshair turns red when you are close enough)