It’s not only a very strange choice but a non-efficient gear system. UNACCEPTABLE.
Jokes aside, it can be extremely tricky to ilustrate things, to find out, just try to come with ideas for etheral concepts such as realism, goodness and what not.
For realism I think I would go for a rather simple landscape, kind of a valley with people doing simple chores such as gathering fruit or maybe for such simple representation in a tiny icon a simple stick-man with a hat and a suitcase, like he’s going to work.
Maybe the formula of some physical law?