The theory in visual merchandising is that mannequins are "silent salespeople", reflecting the aspirations of customers and, thus, enticing them to buy.
Um ... as non-profit organisations, charity shops obviously have a different perspective, as least that's what the above picture suggests. You certainly don't need a degree to work out that a mortar board and naked model equals something a tad kinky!
This naked girl has been living next to the change rooms at the Salvation Army in Fyshwick for years, appearing in a different incarnation of disarray every time I drop in. As a volunteer in my local store, I can tell you that Salvo's staff definitely have a very keen sense of humour!