You are at an expo; and after you say your size, a volunteer picks it out of a mini-mountain of them and hands it to you, after which you stuff it in your token plastic bag, or maybe you hold it out in front of you with two hands, size it up like a painting, then decide in seconds whether it’s a keeper, a rag, or ironic.
It could be short sleeve, long sleeve, cotton, “technical,” designed by a budding 10-year-old artist, or be pure retina-burning color. But that’s not the point.