When someone votes to close a question, and I agree that it should be closed, but for a different reason, and the question ultimately is closed, the box displayed suggests that I agreed it should be closed for the original (or most popular?) reason. Since that box should serve to show the OP what they need to do to get their question reopened, I think it would be good to:
- Allow each closer to choose more than one closure reason,
- Allow users voting against reopening to choose a reason different from the original one, and
- List all reasons chosen in the box.
As it stands, something may be closed as "unclear what you're asking" or "lacks context" when it's also actually not about mathematics and thus has little hope of ever being reopened. Making that clear to the asker could save them the work of clarifying or adding context to such a question.
Note: Although this has happened several times, the most recent was https://math.stackexchange.com/questions/505198/how-to-statistically-model-evolution#comment1084600_505198, which was closed as unclear, but which I believe, if clarified, would ultimately turn out to be off-topic (it looks more like a creationist polemic than a bona fide mathematical question).