Minecraft wiki entry for Resource_Pack, associated text: The old pack.png file was screenshotted from Alpha v1.2.2, the seed being 3257840388504953787.[8]
The screenshot was taken approximately at X=49.16, Z=0.72, facing RX=-119.23, RY=-8.297.
How to generate the exact same world and make the exact same screenshot: https://pastebin.com/CmsEKDev.[9]
It was referenced in the video "One Trillion Minecraft Views on YouTube and Counting".