You're not missing anything because there's nothing that would be impossible.
Instead of keeping kicking this post out of the pool again & again like a JERK; try explaining how she can wear that tight neck T-shirt despite those horns, using a legit reason, not lame excuses like "there's invisible buttons", "it's a magic t-shirt", "she uses her ability just for the sake of wearing a T-shirt" or "there's nothing that would be impossible".
"she uses her ability just for the sake of wearing a T-shirt"
I'd call that a perfectly legit reason for it to be possible for her to wear the shirt - but because that would mean it takes magic for it to be possible, I'd also call it a good reason to leave it in the pool.
I'd call that a perfectly legit reason for it to be possible for her to wear the shirt - but because that would mean it takes magic for it to be possible, I'd also call it a good reason to leave it in the pool.
The pool states specifically that it must go against the internal logic of the world that the character is from not just the logic from the real world.
Oh snap: 1) A shirtless Suika does a head-tilt so that one of her horns is pointing up. The other horn will be aligned with her shoulder. 2) Suika puts on the t-shirt: The horn that was pointed up is already free. 3) Suika pulls the t-shirt collar with a finger and pulls her other horn free.