I am not entirely sure whether this can be asked here, however I will give it a go. I have seen that most of the SE sections have very pretty designs for the up-down vote arrow buttons, that are most of the times related to the subject the page deals with. Physics should pave the way for that, but we seem not to have a particular fancy one. Has this been a choice to maintain sobriety or is there any idea to modify them in the early future? What do you think about it?
If you check out some of the related questions at the right, you can see the history of how we came to our current design. A few people proposed ideas for themed upvote/downvote buttons, but none of them were particularly compelling. And after our first site design (which was considerably more physics-themed) turned out to be difficult to read and use, the community at the time decided we preferred a simpler, more generic design that stays out of the way and lets us focus on the questions and answers.
So basically, I think the reasons for not having themed voting arrows still apply.