http://en.wikipedia.org/wiki/Parkinson%27s_law_of_triviality
This is about how some managers feel they have to suggest a change, any change, to justify their position.
Bike shedding is excessive discussion in committees/group emails about trivial matters because everyone feels they understand the issue, unlike more complex issues up for discussion.
The project manager needs to show that's he's here and actually doing things, and so decrees changes like getting rid of the duck or changing the color of the buttons from taupe to mauve. In bikeshedding, all the people commenting need to prove that they're there and contributing, so now everyone is suggesting color changes. It seems to me that the main difference is the number of people involved.
http://www.johndcook.com/blog/2011/03/03/thomas-jefferson-me...