I wouldn't lose too much sleep over the video, even if you "bombed" it. It's not even the fourth-most important aspect of the application. They won't reject someone they would ordinarily accept because of the video alone.
Just submitted RD- mine was something like "What is a major trend you see in your chosen field/area of study?"
Looking at the other prompts above I don't think anyone needs to worry about getting a real policy question. 60 seconds to prepare and 60 seconds to speak isn't nearly enough time. Despite practicing multiple times I still got horribly flustered watching the red timer tick down. I was accepted last year and my CV has only improved since then but I'm now seriously worried I've ruined my chances this round with my sub-par performance. :/
Dias got a reaction from lilyco in SIPA Video Response