Disney has released the first Frozen II poster. The upcoming sequel sees Anna, Elsa, Kristof, Sven, and Olaf going on a new adventure to discover the source of Elsa’s magical powers. What’s interesting about this poster is that it’s a little more mature. It’s still a Disney movie, of course, but it understands the need to seems a little more serious and dramatic because the audience has aged up. If you were a seven-year-old in 2013 who was nuts about the first Frozen, you’re now in middle school, so the question becomes have …