I guess under all the packaging it’s one naked person underneath. If we’re just talking about the shirt, generally people are wearing more than just the shirt because usually just a t-shirt doesn’t appropriately cover up everything that needs covering. But, the shirt makes sense if you consider all the clothes as the packaging with the contents being your body, which, when it doesn’t have clothes, is considered naked.
I can go on another 2000 words going deep on this if you like. Tell me in the comments if that’s what you need. Otherwise, I’ll let it stand where it is.