Click Activity log in the top bar to see recent copy operations. Each entry shows the status (Completed/Error), the source, when it ran, who ran it, and how many destinations were affected. 
 

Expand an entry to see, per destination and category, exactly what was Added, Overwritten, or Skipped.

To undo a copy, click Revert on a log row:

• Revert is available for 90 days after the copy.
• It removes items that were added and restores overwritten items to how they were before.
• If someone changed a copied item afterwards, you'll be warned before it's removed and can cancel or choose Revert anyway.