In a similar manner, the dogs that ceased to move their tail mainly did so in the unwilling-condition. Ceasing and slowing down tail movement has been interpreted as signals for attentiveness, and attempting to make sense of confusing situations
This part of the text explains that in the unwilling condition, dogs will stop waving or reduce the frequency of moving their tails during the experiment. This action can be seen as a messege to researchers that dogs are concentrating to understand what condition is happening before starting their action.