Any reference to an image file on a generated page is handled the same way - the browser will make a request for the second time to the image source (on the server) to retrieve the image - this happens irrespective of if the page was generated by a single jsp servlet (such as in include directive) or if the page was generated by a jsp servlet which included one or several other jsp servlet response via jsp include standard action.
In summary, if you change the image file on the server, in either case you will see the most recent image file (unless caching is turned on, then in both the cases you might see the older cached image).
However, note that I am aware of the fact that, say you have J1.jsp which includes J2.jsp, then with the directive, if you change J2.jsp, it will continue to use the content of older J2.jsp (which is now part of J1.jsp) until you change J1.jsp or delete the geneated J1's servlet class file.
Having said that, I don't think the question was realted to generating dynamic content by changing the file J2.jsp. When generaly "dynamic content" (such as jsp file) as against "static content" (html file), is being referred, "dynamic content" is generated not by changing the underlaying file on the server, but by variables such as the specific user who is making the request or other variable factors such as time of request etc.
In summary, my comment is that you can generate "dynamic content" in both cases - option A and B.