[BSchwarz]

Our previous post about the new copy experience in Windows 8 generated a lot of questions and comments about the new “Choose Files” dialog for resolving file name collisions. Based on the level of interest, we thought it would be fun to share some of the design iterations and our usability testing that led us to this design.
In the implemented design, there are two levels of control when acting on file name collisions (or “conflicts”).

• The primary experience is a simplified, one-click, bulk management of all conflicts, offering “Replace all” or “Skip all.” We call this the “Simple Conflict Resolution dialog.”
  
• There is also an option to enter the secondary experience which offers more information and more fine-grained control. This is the “Detailed Conflict Resolution dialog.”

Source: MSDN Blog