On my iPad, I don't see any difference between the size of the last two pictures. I agree the first one is to small.
Are you sure you are still saving one image to your hard drive that is full size?
I usually have two copies. The full size one just has the flower name. The smaller one has the name with _web.jpg at the end. I do two because I have a web page away from DG or Cubits that does not downsize first.
I do know that downsizing photos first WILL make your upload time here quicker.
If we keep plugging away at this, we will figure something out!