This is clearly not that; everyone knows that the common icon for a heart is a cartoon. I - and probably most people - was not aware that the common depiction of butterflies is in a form they rarely take during life.
Funny story - just the other day my 4 year old daughter was wondering if the hearts in our bodies looked like the shape she knew as a "heart" because it didn't look that way in the Magic Schoolbus episode she'd just watched about Ms Frizzle's vascular system (where the heart was depicted in a more-or-less anatomically correct manner). It was an adorable moment.
Yes, yes. I was just poking fun. Like the other commenter, I too have small kids and have had to explain to both of them the shape of the human heart and how it differs from the heart shape.
I always thought it was supposed to represent fusing 2 hearts together. A bit grim but hey...
https://i.imgur.com/5DtIqYg.jpg