I think they may been older models which have been moved out to make room for the new collection -- there are still some older models in the clearance section, although very bitty in which sizes are still available.

There are some low square heel models which sorely tempt me, but I definitely want to try at least one of them on before buying, rather than order online. The King Street shop is open until 6, so it should be easy for me to pop in after work.