You do not need pictures, but if the Service Center lost your pictures or the Interviewing Officer thinks there is something wrong with them, then the Interviewing Officer will not be able to process your application further as you need to sign them when you pass your interview.
The original divorce decree is similar. I had enclosed a copy of my decree with the application, and was not asked by the Officer for the original. However the Officer has the right to ask to see the original documents related to your application.
So you could be ok without either, but if they ask then your final approval might take longer until you can provide what they ask.