It's fixed gear. It doesn't seem like she's pedalling at the start because the gear ratio is soo large, so large in fact the bike can't even be pedalled at speeds less than 15mph.
The pedals continue to be pushed forward when the rear wheel is rotating freely. With a freewheel, this shouldn't happen (the pedals can drive the rear wheel when they're moving forward but not backward, while the wheel can drive the pedals backward but not forward).
But I'm still confused about the lack of visible pedal movement during the initial towing part of the record video. It seems like she was towed more than far enough that the pedals should have needed to move visibly with a fixed gear.
