The filename is frequently used in technical documentation as a for reproduction steps:
In video production and web development, "640" is a standard width for or "mobile-ready" video. 640.mp4
: It has appeared in bug reports for media players like mpv , where users use 640.mp4 as a test file to demonstrate hardware acceleration or permission errors (e.g., "VT_GETMODE failed") on Linux systems. The filename is frequently used in technical documentation