So, the quick, less-clever photos. First, the object: it's a quick little button-on cowl. Except it isn't.
The back, you see, is nice stretch ribbing. And the buttons work - but not to disassemble the cowl into one flat thing, as with most button-on cowls. The buttons open the SECRET POCKET.
... and I think that's it for me doing six classes in a month. I love you, Slytherin housemates, but I really have to finish my OWLs!!