This link also helped me parse Rich's previous tweet about "diverse backgrounds" in the Kickstarter project called Prismatic Art Collection. "Why do I care whether the artwork shows the heroes standing in front of a sky or a forest? Ohhhhhh."
Look, just because the game originated by depicting cool and temperate climates does not mean that we can't depict warmer terrains like deserts and jungles. Fantasy art does not have to only show the landscape types found in northern Europe in order for gamers to identify with it!