WOW, the most misleading thing I have watched in a very long time.
At first I thought it was about work life, and how it can be depressing or that poor workers work their asses off day and night and managers/bosses sit all day with nothing but ordering them around.
Then I thought that the title means that no matter how bad things get, with patient and by looking at the full half of the cup you can achieve positive results (after seeing how the manager got upset about how bad the sales went)
But damn, that ending totally got me, creepy yet funny in a way.
All in all this is a great masterpiece, with beautiful animation and music. Also I feel that this animation is very similar to "Don't Hug Me I'm Scared" video.