This video clip is a quick look at the shape of the flow/volume loop, specifically the inspired portion of the loop. Peak inspiratory flow and the overall shape of the inspired curve are effort dependent. Poor patient effort can mimic the same shape or pattern on the inspired loop as a variable extra thoracic obstruction (large airway obstruction). In both these cases there is a flattening of the inspired loop, which you will note on the video.
This is why it is so important to emphasize maximal effort on inspiration as well as expiration.