Chinese electric vehicle (EV) maker Xpeng Motors showcased its humanoid robot in front of hundreds of onlookers at a mall in the southern metropolis of Shenzhen over the weekend, but a backwards flop became headlines, reflecting the bumpy journey ahead for such machines.

After completing a smooth catwalk to the centre of the audience on Saturday, Iron, the 178cm robot said to walk with humanlike grace, lost its balance and fell backwards when standing still on the stage, according to multiple videos circulated online. A staffer broke its fall and it ended up face down on the ground.

Staff quickly carried it away, and it returned after adjustments to complete interactive performances with children, asking trivia questions like what colour a giant panda’s poop would be.

On Sunday, the second day of the campaign, the machine did not walk, but instead was strapped to a frame during educational and entertaining chats with the audience.

Despite having walked without incident several times during its Saturday appearance, the robot’s plunge made headlines. It was the fourth most searched topic on Baidu on Monday morning, and the top trending topic on Sunday night on ByteDance’s news platform Jinri Toutiao, according to data from Entobit.cn, which tracks social media.

“It reminds me of how all toddlers learn to walk,” He Xiaopeng, co-founder and CEO of Xpeng, said on Sunday on microblogging site Weibo. “After a fall, they will stand firm; the next step is to begin running, and to keep running.”

Non-humanoid robots represented by robotic dogs had achieved commercialisation faster than humanoids, GF Securities said in a report last year. “Compared to bipedal humanoid robots, quadrupedal robotic dogs possess higher payload capacity and exceptional balance capabilities, while also being easier to control, design and maintain,” it said.