Go back to your house and go into the living room. Wait and answer the phone just this ring and, once finished the dialogue, exits and entrances to the bathroom. Press the switch next to the door and use the photos with the device on the table. I recommend you save at this point or you may lose photos, forcing then having to redo. To develop the three pictures you have to do is select one of the sheets on the left, press on the device and you will see that the photo will be automatically put in the tank with the liquid; wait until the picture becomes clearer and click that to develop it again. Repeat step for the other two photos, and when you're done, go back into the living room to answer the phone by selecting the first sentence. After the dialogue back to the building RSHA and show photos to Muller.