My T used to video record my EMDR sessions because he needed so many recorded hours for certification. He asked me to sign a waiver if I consented (which I was fine with) and he asked verbal consent again each session. He said I could withdraw consent at any time. I was actually happy because I knew he would be reviewing my sessions in supervision and improving his skills while getting the best advise. For me this was very helpful as I am a difficult case due to my DID and extreme flat affect.