The answer is never.
When uploading an image using the image uploader, a Thumbnail object/record is created which is referenced. This is used when displaying a thumbnail.
//Edit//
Did some debugging and source inspection.
The URL of the full image = {AppURL}/file?guid={Guid}
The thumbnail URL = {AppURL}/file?guid={Guid}&thumb=true&name={FileName}
Based in this you can easily construct the Image and Thumbnail URL by capturing the ObjectGuid and the file name
Hi..
I am also Facing a Similar Problem..
When i see the Database the Thumbnail path for the images are empty.
Do we need to do something to Store the Thumbnail path while uploading an image ?