We have teleconferences all the time at the company I work for. For years, it was usually just audio, but video is starting to ramp up. I guess it's because we don't meet in person at all now, and some people "need" the face time. Someone calling in from their car wasn't that unusual.
Anyway, I think Jennnifer was used to audio-only, and didn't even think about the fact that she was on video. That's the only thing I can think of.