Amid the drumbeats of enthusiastic propaganda for the Expo that have dominated Shanghai in recent months, it has also been possible occasionally to hear a different tune about the city's future.

A couple of months ago, a gallery launched an exhibition that sought to have some playful (and sometimes not so playful) fun at the expense of the event.

One sculpture was made from the household goods sold by street vendors who have been cleared from the city centre for the duration of the Expo, while the centerpiece was called “Bubble city, Bubble Life” by Chen Hangfeng, a large cage with a machine inside. At regular intervals, the machine spewed out soapy bubbles that floated around inside the cage until they hit the wire and burst. “Bubbles are light and colourful and full of fun,” says Mr Chen. “But, like the utopian ideas that surround the Expo, they are also fragile and easy to pop.”