2-disc gift set

[Pippin]

I have 1-disc full screen DVDs of the 5 movies and am thinking about 
getting the Harry Potter Years 1-5 Limited Edition Gift Set (2007).  It 
comes on 12 discs, and the frame is widescreen.  But I haven't found a 
clear, detailed description of the additional content. Can anyone 
enlighten me or point me toward a complete description?

The best I've found is this:
The Harry Potter Limited Edition Giftset includes Harry Potters Years 1-
5, a Harry Potter DVD game Hogwarts Challenge, along with a bonus disc 
containing over 2 hours of enhanced content, an exclusive "Harry 
Potter's Bookmark Collection", and collectible trading cards.

So, to narrow it down, I'm wondering what is included in 'over 2 hours 
of enhanced content'.

Pippin Fowler