Genevieve von Petzinger’s Why are these 32 symbols found in ancient caves all over Europe

Watch the video, Genevieve von Petzinger’s Why are these 32 symbols found in ancient caves all over Europe?, and answer the following questions:
What type of imagery were von Petzinger and her husband focusing on in their research? Why might this type of imagery have been overlooked or disregarded in earlier discoveries? How might the closer inspection of these images and more detailed classification systems be beneficial?