You choose not to use the appropriate software to experience what is being offered. This is akin to riding a decrepit horse on a racetrack while whining about how everyone else that is riding a healthy horse is going faster and having a better experience than you.
Your analogy is stupid and your comments are not helpful. I'm not modifying 3,600 workstations because some web programmer decided to mangle user-uploaded content without doing fundamental work to ensure graceful degradation.
you're seeing that because they wanted to show you what it looked like as an MP4. My understanding was that twitter would ship you the GIF if your browser didn't support MP4.
Just upgrade.