Just to add to this: if the gallery app wants show a still of a video at full size, asking for a thumbnail at (0,0) actually makes sense because there is no sensible way for the gallery app to pull out a still frame. For photos, it would be nice if the gallery app were to open the image file directly. That way, we don't end up with the image on disk twice (once in the original file, and once inside the thumbnail cache).
Just to add to this: if the gallery app wants show a still of a video at full size, asking for a thumbnail at (0,0) actually makes sense because there is no sensible way for the gallery app to pull out a still frame. For photos, it would be nice if the gallery app were to open the image file directly. That way, we don't end up with the image on disk twice (once in the original file, and once inside the thumbnail cache).