The intro summary does a good job at summarizing some quick info about the painting including the location. Its also good that you dont just repeat the same info again in the other sections.
If you are gonna keep the Other Versions part then maybe you could do a short compare/contrast between the two. Or maybe you don't really need a section about the other painting and could focus more about the model and a little more info on him.
In your Model heading 2nd paragraph you say "various art historians," you should probably at least mention that the author from the reading is making that assumption since no specific historians are quoted in that sentence. Wikipedia doesn't like vague/unspecific people stating info.
Need a couple more sections. Not sure about keeping subject matter section if not too much is added to it. Could do one on Caravaggio's style and techniques he uses and place between the Commission and Model sections.
For Subject Matter, you could try to find out why Caravaggio was interested on that subject since he painted two of them. Was it his or the Cardinals request to paint Bacchus, then that section would fit better preceding the Commission.
