Xiaoying_video_1629617123662mp4

Here is an interesting look at the context of this type of file: 1. The Story Behind the Name

It is likely optimized for mobile viewing (9:16 aspect ratio). XiaoYing_Video_1629617123662mp4

This translates to "Little Shadow" or "Little Film." It is the parent company (QuVideo) and the original Chinese brand name for VivaVideo [1]. Here is an interesting look at the context