JD.com's expert short video is a short video marketing method launched by JD.com, which allows users to promote their products or services by shooting short videos. The specific gameplay is as follows:

1. Log in to the JD.com expert platform, fill in personal information and upload product information.

2. Shoot a short video, the length of the video should not exceed 15 seconds, and the content should be related to the product or service.

3. Add the JD.com expert watermark to the video to ensure that the copyright of the video belongs to JD.com.

4. Upload the video to the JD.com expert platform and fill in relevant information, such as product name, price, promotion information, etc.

5. Share the video to social platforms, such as WeChat, Weibo, etc., to attract more users to watch.

6. Get corresponding rewards and commissions based on the video's playback volume and conversion rate.

In short, JD.com's expert short video is a new marketing method that allows users to promote their products or services through short videos to increase exposure and sales.