I’m just a sucker for weird symbols and numbers. The left clock has an explanation of each expression underneath it. “3” is represented by π (3.14…) and a blue dot on the outside of the circle where the numerical value would fall (just below the 3 position). The other expressions are the same way (for example “6” is Avogadro’s number, which is 6.0221415 × 10^23.) The right one isn’t as clever about the expressions and placement, but I think I like the symbols just as well!