Yoda Is Your Father said:
Looking at that picture the problem is the helmet is too big for the body... not dissing Hayden but Prowse was a bodybuilder - a big guy. They should have gotten somebody bigger to play vader at the end of ROTS. But like auntie said, who can blame Hayden?

Definitley looks wrong though. And don't get me started on the Emperor... geez.

Or the REALLY creative way to go, since they had to build a new costume for Hayden anyway, would have been to downsize the entire thing proportional to the size difference between Hayden and Prowse - in essence, scale down the costume proportional to the body, like the way they make smaller versions of halloween costumes for kids.