facet, salient

facet: （宝石などの）小平面, （人・事の）一面
salient: 顕著な, 目立つ

After a few minutes, we hit upon a facet of the game we agreed was salient to Nisenholtz's point -- it is the most advanced example of a medium people create by merely participating in it.

EPIC 2014: The Future is Nowより。