This specific numeric format is how Discord renames files uploaded to its servers. If you found this in your computer's cache or a shared folder, it likely originated from a Discord chat.
If you are looking for a review because you found this file on your device or were sent it anonymously: 5125212941360038568.mp4
Because this is a generic system-generated filename, there is no single "official" video or review attached to it. However, Why this filename exists This specific numeric format is how Discord renames
If you have the file and want to know what it is without playing it: 5125212941360038568.mp4
A very small file (under 1MB) is likely a short meme or a GIF-style loop.