If the video consists of multiple files, the different components of shape refer to different files. In case of P2 or Avid OpAtom, there are components for the video MXF and each audio MXF. In case of P2 all additional files that are part of the P2 structure (e.g. proxy, XMLs) need to represented by a separate shape for each file.
Referenced MOVs follow the same pattern: one shape for the MOV container and multiple shapes for each audio or video file referenced by the MOV container.