user
Given a cartoon image and a caption. Caption: I think it's just a phase. Question: Generating an explanation of why this image/caption combination is funny. Answer: 
assistant
A play on the term "phase" --- the moon (depicted here with a winking emoji) experiences phases in the form of the light patterns from the sun that are, e.g., waxing or waning. But here "phase" means an emotional phase --- a person (particularly a teenage) might be "going through a phase" if they are acting strangely. The moon is going through an emotional phase by acting strangely, i.e., by having a winky face.