Hi Steven,
One way of doing it is ...
1. Upload an image using the image tab
2. Set the image to hide in item view in category listing
3. Have another image in your item content, and separate the image with hr readmore (introtext)
4. Now, if you want to show both images in item view, just set the introtext and image to show, or you want to show only the image uploaded using the image tab, set the introtext to hide.
K2 Rocks \m/