Where do I see the progress of an ongoing restore?

The location of the progress bar depends on who initiated the restore:

Non-admin user - When performing a restore of your own backup data, an orange progress bar displays at the top of the 'Restore' tab in your user account.  This progress bar shows the current progress of the data restore.
 
Admin user - When performing a cross-user restore of backed up data from one user account and restoring into another user account in your domain, the progress bar displays in the admin user's account, in the Restore tab.  The progress bar is displayed in the admin user's account since that's the user who initiated the restore.