I am the petitioner. I had planned a visit to see my fiancee in Makati and we got very lucky and we were able to schedule her interview while I was there. Our pre-interviewer just asked to see my fiancee's paperwork and asked to see my I-134 and also my tax information. She asked a few questions like are you married/do you have children. She asked if we had pictures of us together and when we responded that we did she said well just hang on to them for your interview later.
The second interview with the American took only 3 minutes. He asked whether we were single and if we had children and he asked my fiancee about how i proposed to her. He did not ask for any proof of relationship at all. He could tell my fiancee was very nervous and he politely told her to take a deep breath and relax because he was going to approve her visa. The interview took only 3 minutes and my fiancee never even realized that her visa was approved. She asked me if there would be another interview and I told her no, you are approved. She was shocked because she had heard that the interviews are very hard, but ours was not. I don't if it was because i was there or because she had a very big organizer full of documents, pictures, chat logs, etc. haha!
The only bad part of the morning was the very early start time and the very long wait outside without any seating available. Overall, it was a very enjoyable adventure.