These are two pieces by artist Antony Gormley. The first is called Blind Light and involved the audience entering a glass room filled with fog. The second is called One & Other. For this the public were asked to stand on the fourth plinth in Trafalgar square for an hour, accumulating to 100 days altogether. During their hour on the plinth the audience could do whatever they wanted(within reason). The idea was the contrast of the military connotations of trafalgar square and about contrasting that with the elevation of everyday life.