I think I've said this before, but "passenger of size" is one of my most hated euphemisms.

I'm a passenger of size too, my size is "medium", which is why I fit in a seat designed for actual human beings.

I've never met a passenger of no size. Though admittedly it's possible that they exist and I've just never noticed one what with their complete lack of spatial extent.

On that note I'm also a person of colour, and my colour is a sorta light pinkish brown like most other people of north-western European ancestry.