A lot of times people watching demos often question what is shown. Suggesting compliance, faked or exaggerated effects done for many various reasons most of which do not really explain why someone would do this.
Feeding Jin, this has to do with the way and type of power the demo works with or on. Yi to yi, qi to qi, li to li “yi= intent, qi = inner power , li= integrated whole body power” A lot of what is seen depends on the teachers skill level and the level of the student.