A unit of the expo sensitizes China's manufacturers to shapes, sizes and branding

At the Canton Fair, or the biannual China Import and Export Fair in Guangzhou, Guangdong province, chubby robots move around and invite passers-by to check the oxygen level in their blood. They offer help to those needing an oxygen boost.

Nearby, screens cover a booth with 2,500 green acrylic tubes. Visitors throw curious glances, wondering what's inside. Behind the curtains is a 3-D printer that produces ... chocolates.