It is natural to want to write exercises that rely on graphics. For example, an exericse might produce a chart of some kind, and ask the reader to extract some information from that chart.
At present, this can be done using the same mechanism one would use to insert a graphic into a WeBWorK problem when writing regular WeBWorK problems. (And this is what is done below.) In the future, there will be a nicer option that will be able to make use of MBX's latex-image-code. This requires some WeBWorK development first, which is underway.