Imagine if "Math and Fire" (or its Latinate equivalent probably) becomes the motto of whatever organization is responsible for human rocketry in the future
And the fact that some of the duplicates aren't the same size. Aliens, shit, I'm confused by that one
We have five lung lobes because fuck anyone taking a human anatomy course, I guess? Don't even get me started on the sheer weirdness of the liver.
I'm now imagining aliens with advanced biotech being vaguely appalled at not just humans, but any other species that isn't genetically engineered to be more efficient. "Ha, yeah, there's a bit of our intestine that doesn't actually do anything but sometimes get infected and burst and kill you." "What."
Also, fun fact: the typical kidney transplant procedure is literally "just stick it in wherever there's some free space". I can imagine an alien being horrified at this.
"So your species exhibits bilateral symmetry?" "Well, kinda. On the outside, sure, mostly, but once you get inside things start getting weird." *Alien, having studied humans and their culture extensively but only just now learning about their biology* "...weird how?"