A caterpillar turning into a butterfly
represents males becoming more and more feminine, internally, until they eventually fully transition to female. It's just a metaphor for a dick turning into a vagina, a man becoming a woman.
This occurs when a man begins to seek more and more attention in order to be fulfilled, which is a feminine trait. They want to be deemed pretty, want to be loved, care what others think about them, etc. They become more delicate, like a butterfly. More mental, less physical (in the air, vs on the ground).
There is the whole Monarch Mind Control angle, and there's definitely something to that and it may even relate to what I'm theorizing here. Somehow the mind control is set up to get males to believe they need to be a certain way, act a certain way, do certain things to gain the affection/attention of others, until they're completely brainwashed and become more feminine in nature.