Currently, all but one plotting question is tagged with graphics, also. Per the prior discussion, I don't think this was what was intended. Is this what we intend to happen, or should the distinction between the two be made more clear?
I think of graphics as being the super-tag, with plotting, image-manipulation being sub-tags. I can also see situations where you would use the graphics tag but not either of those two, e.g. when the question is about exporting graphics.
Since one can add up to five tags, I think the double-tagging is a reasonable solution.
EDIT To clarify, I think of graphics as being a good tag for people to follow when they are looking for questions to answer. I see the narrower tags as being better for looking for existing questions when you are trying to see if your question has already been asked.