In the mid-2000s, video streaming was choppy and data was expensive. Users didn't "watch on the cloud"; they downloaded files to their hard drives.

The source platform. Mentioning the platform in the filename was common for "scene" archiving.

Here is a deep dive into the history, the context of the file name, and why these "portable" video clips became such a significant part of early web culture. The Stickam Era: Where It All Began