I'm sorry they're both twinks but, they're not shotas, it's just a cute moe art style. It's a cuteness obsession.
I can never understand people who equate super cartonish styles to... real people bc they most certainly don't look alike. Or the fact that this gen throws around the word pedo so casually. Pls reserve that for real pedophiles.
(Also, most men in Japan aren't even realistically built tall or buff, they're like 5,7' at best )
Every art style is different; and have different in-world variations for what they consider adult, teen, child. This specific style is a very popular generic style shared among many shoujo/BL illustrators because the charm point is big eyes, cuteness and slenderness. An actual 13 y/o in this style would look very different.
As an extreme example, other series like Simpsons, Layton, Jojo, Lucky Star, etc...are all very stylized diminutive artstyles, but still have their in-world variations for different ages.
All this says is that all styles are the same to you; and therefore the same standards for what looks adult or child is the same across any genre.
Your opinion is your opinion, and I can't change how you feel. It's just a bit culturally insulting.
bro built like a child um the sex made me rlly uncomfortable since it looks like two minors doing it (especially the uke).. the top looks handsomely cute tho