Looks to me like that image has been croped from its background(most likley the Bespin hallways),the spikes have probably been croped with the background.
That plus the fact that the toe on the left foot can hardly be seen,and the right foot is faceing away.
Another thing is they may well be that they had fallen off,as so much of the costume did on set. The knees were a constant problem!!
FMF