The company who put together this short is Purple Feather. http://purplefeather.co.uk/
A purple feather is an item that means very little to the average person but means a great deal to a specific person. To give a purple feather is to give someone something that means a great deal only to them.
What a powerful message.
Thank you, Heather O, for the link.
For my definition, I found this site http://purplefeather.com/why.html