This graphic has been circulated on social media for a while:
I must admit, I smiled when I first saw it. But if you stop to think about it, the graphic overlooks a more serious point.
Of course they are both unattainable, idealised body types. But what are they ideals of? Barbie's body represents an ideal of beauty, whereas He-Man's represents an ideal of strength.
Strength is an active quality. If you are strong, you can rescue a child from a burning building. You can build a house, sail a ship, slay a dragon. You can be a hero.
Beauty is a passive quality. If you are beautiful, then at best, you can persuade other people to rescue children, build houses, sail ships, or slay dragons. You can be the decorative reward for the hero.
Moreover, there are many ways to be strong and athletic without looking like He-Man. Mainstream standards for feminine beauty in our culture are much more narrow. Telling boys they should aspire to be strong, and girls they should aspire to be pretty, is one way sexism gets started.
To be clear, there's nothing wrong with a person of either sex wanting to be beautiful. It just doesn't strike me as a great idea to promote it as the most desirable goal in life.