Refreshing PowerPivot Gallery thumbnails

Let's assume that for some reason something got corrupted and you want to regenerate the thumbnails for a given workbook in a PowerPivot Gallery. You can either change the properties for the workbook, which will create an event that will trigger the regeneration of the thumbnails (more details at Dave's blog here: http://bit.ly/9Z23pt). Under the hooks, adding a new document to a SharePoint library (PowerPivot Gallery included) or modifying a document in a SharePoint document library causes SharePoint to throw either a itemAdded or itemUpdated event. The event is observed and handled by PowerPivot, which calls the GetSnapshot.exe as the farm account passing along a few parameters.