Pay attention to the prohibited items listed on USTravelDocs- No cell phones, laptops or other electronics.
Very busy Embassy. Took 40 minutes to get through security stages. Interview scheduled for 6:30, waited until 8:30. Interviewer visibly annoyed and frustrated during interview. Said "I want to hurry" when beneficiary was providing her the requested original documents.
Given a 221g for lacking i-864 supporting documents-- which was uploaded to CEAC and present at interview (but perhaps lost in translation).
From the faces in the embassy, a lot of denials were happening.