Add or Remove photos dynamically from within FlickrExport

It would be useful to be able to add and remove photos from the export window list on the fly. There are times when I select some photos to export, add descriptions etc. and then realise that I'd like to add another photo to this set, or remove some. It seems the only way to do this now it to cancel the export and reselect the correct photos, which means you have to re-enter the information.

If FlickrExport wasn't something like a dialog window, so that you could access the iPhoto window while having the FlickrExport window open, then using drag and drop to manage the photos? I think maybe this is impossible for it to be a separate window if it's a plugin?