“This photo of Liu Qiangdong is called a mug shot,” a blogger and journalist who goes by the name Michael Anti wrote on WeChat, the ubiquitous Chinese messaging and social media platform. He went on to explain that mug shots were considered public information in the United States, and can be released to the media.

Descriptions of “probable cause” and “released pending complaint” were also widespread. There were even photographs and audio recordings of Mr. Elder.

Others speculated over Mr. Liu’s marriage to Zhang Zetian, who rose to fame as a student when a photo of her holding a cup of milk tea was widely shared on social media. Nicknamed “Sister Milk Tea,” Ms. Zhang met Mr. Liu while she was studying in the United States, and they married in 2015. The couple have been both praised and criticized in China for cataloging online the intimate details of their lives, including their wedding and Ms. Zhang’s pregnancy.

Mr. Liu’s arrest also prompted derision. In a previous video interview, he had insisted he had not married Ms. Zhang for her looks. “I am face blind,” he said. “I can’t tell who is pretty and who is not.”

Referring to those remarks, one online user joked, “Maybe he mistook the other woman as Sister Milk Tea. He is face blind, after all.”

Beyond online comments, the case also put a spotlight on JD.com’s fierce rivalry with the Chinese e-commerce giant Alibaba, and in particular the clash of personalities between the companies’ founders.

If the most intense reality show in the United States is national politics, business feuds take top billing in China. The workings of the government are carried out in a black box, off limits to media scrutiny and public discussion, but antagonism in the business world is carried out in the open. Among the business tycoons, the heads of China’s internet companies are the hottest stars, the leaders of JD.com and Alibaba chief among them.