How about we do it this way, again using Porsche's site and some real images:
Personally, I'm not seeing what The Radium King was pointing out, because to me aside from the differences in the nose, side vent slots, and the raised spoiler lip on the Cayman, I'm not seeing enough of a difference of note that suggests that the Cayman image was shopped to make the Boxster image in the Build section.
Can you help me out, Radium?
EDIT: I re-read and saw what you mean about the "Hockey Stick" on the Cayman. So yes, poo poo on us indeed.