This is a good example of how a gif can be properly created to give the appearance of continuity, even though this is a series of images stitched together as a GIF.
Poorly Created GIF
because the model is not in the same position at the beginning and end moment... the repeat becomes apparent and distracting.
Still Motion Effect
It is possible to create a still image where an element in the image is in motion—cool effect.
Source: google image search