A tree can be a tree, but it can also be a psychopath. The tree goes from being a regular tree to being a psychopath. Such mood swings are so rough. Especially when the tree slips to gloom.
Then the tree switches from gloom to being super excited (these moodswings!). The super excited tree starts doing dubstep. Uts (うつ) uts uts uts uts ♬.