As she gazed down from a bridge at the rapidly flowing river, nancy felt as thought she were moving. her experience best illustrates the phenomenon of:

Her experience best illustrates the phenomenon of "visual capture".

In psychology, visual capture in the field of psychology refers to a scene where the vision overpowers other senses in forming a perception. In this procedure what happens is that the visual sense affects the other parts of somatosensory system which ends up in a supposed surroundings which is matching with the reality.