 The pivotal penis drawings were a bone of contention with the  MPAA, particularly the scene with young Becky holding an image of  one of them. Producer Judd Apatow (qv) elaborated it was the  subject of much legal wrangling, including how erect they could be,  if veins could be shown etc. The actress playing young Becky however  has a different picture to hold before we cut to the actual drawing.  You can even see from the reverse that the drawing she holds appears  completely different.