I had a suspicion that this might be happening, so I made a dummy item with a specific image set, then deleted it. The images still remain in the file system.
I do not have my images stored in the database (imho, this leads to an enormous waste of space in the database), they are stored as part of the file system.
I'm also wondering if it might be possible that instead of uploading and storing an image for each product/varient it might not be a better idea to use a file pointer instead, thereby keeping a separate storage area for images. The current method requires a huge number of images when you have similar products using the same picture.
As an example of this, I manufacture and sell protective eyewear. In one sub-product line, I carry 5 different frames each with 2 colors, for a total of 10 pictures. In my old system (running under ColdFusion), I stored 10 pictures, then linked each product (approx 70 line items) to the pictures. The way things are now, I've got 140 copies of the same picture in the file system!!
Any thoughts?